Polyaxial Plate Rod System and Surgical Procedure

ABSTRACT

A spinal fixation device includes a bone screw, a nut, a bearing, a slider, and a plate construct. The screw has a head with a nut connection and a screw portion. The nut has an exterior wall and a bore connecting to the nut connection. The bearing has an exterior and defines a bore fitting therein the nut connection and the exterior wall of the nut. The slider defines a bore fitting the nut exterior wall therewithin and has an exterior with a given shape. The elongate plate construct has a first end defining a first opening shaped to accept the exterior of the bearing therein and a second end defining a second opening shaped to accept the slider therein and having a corresponding shape to the given shape to permit the slider to slide in at least a portion of the second opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/507,517, filed on Oct. 6, 2014 (which application claims priority toU.S. Provisional Application Ser. Nos. 61/887,676, filed on Oct. 7,2013, and 62/003,615, filed on May 28, 2014), the entire disclosures ofwhich are hereby incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention lies in the field of spinal implants. The presentdisclosure relates to an implant and surgical procedure for insertion ofa spinal implant. More specifically, the present invention relates to animplant connecting member that has the ability to connect multiple bonescrews while adjusting for angulation and distance between the bonescrews. This assists the surgeon in connecting implants at differentangles without bending or contouring the connecting member. Thisprovides the benefits of more accurate and easier connecting of two ormore implants and significantly reducing surgical instrumentation whileminimizing patient trauma and reducing surgical time.

BACKGROUND OF THE INVENTION

The insertion of pedicle screws into the spine for fixation has beencommonly used for many years. In general, a set of implants is placed onboth sides of the spinous process into the pedicles and the set on eachside is connected by an individual rod. For example, in a single levelfusion, whereby two vertebral bodies are intended to be fused together,four pedicle screws are used, two on each side of the spinous process.Each set of two is then connected by the rod. For multiple levels, morescrews are used and connected by longer rods. The general technique isan open procedure, whereby the incision in the skin is long and spansthe length of the affected area of the spine to be treated. Asalternative to rod based systems, plating systems, where a plate formsthe connector between two or more screws, has been used in the spine fora long time. Plating systems, such as those shown in U.S. Pat. No.4,611,581 to Steffee and U.S. Pat. No. 4,887,595 to Heinig et al., userigid plates to connect the screws placed within the pedicles. Rod-basedsystems are significantly more popular for fixation in the posteriorlumbar spine due to the complexity of the anatomy.

The lumbar spine includes multiple vertebrae that, in a healthy spine,are flexibly held within a general S-curve. Each vertebra is a differentsize and different geometry. The pedicles on each vertebra, which areposts that extend from the vertebral body, vary in angle and distanceapart from one vertebral body to the next. While a rod can be contouredor bent to meet the anatomy, this is extremely difficult, if notimpossible to do well with a rigid plating system, as plates can becontoured to match the S curve, but resist contouring in otherdirections.

To avoid contouring, systems such as that covered under U.S. Pat. No.6,379,354 by Rogozinski, break long plates into smaller plates thatconnect one pair of screws at a time. The system is difficult to use andrequires significant implant inventory, as each link covers only onedistance between two screws and has no adjustability. There are alsoother drawbacks such as overall system height and profile

Therefore, while these prior plating systems and surgical procedures canbe suitable for limited usage to which they somewhat address, they arenot suitable to providing an implant and surgical approach that canaccurately and securely connect multiple screws together, adjust foranatomical variations, provide a low profile system, and significantlyreduce the quantity of implant and instruments needed while reducingsurgical complexity.

Thus, a need exists to overcome the problems with the prior art systems,designs, and processes as discussed above.

SUMMARY OF THE INVENTION

The invention provides a new implant system for adjusting to the anatomyof the spine and connecting two or more vertebral bodies securely thatovercomes the mentioned disadvantages of the heretofore-known devicesand methods of this general type and that provide such features bysubstantially departing from the conventional concepts and designs ofthe prior art, and in so doing allow simpler and more accurateconnection of multiple spinal implants while providing a small overallsize leading to less trauma to soft tissue.

The present invention relates to a spinal connecting member. Morespecifically, the invention is directed to an implant connecting memberthat has the ability to adjust to angulation and distance of two or morebone screw anchors and to assist the surgeon in connecting implants atdifferent angles and distances. When the angulation and distance neededis set, the device allows for locking of the angle and distance.

The present invention provides for a plate for attachment to spinalimplants.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants are bone screws.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants are polyaxial bone screws

The present invention provides for a plate for attachment to spinalimplants where the spinal implants are monoaxial bone screws

The present invention provides for a plate for attachment to spinalimplants where the spinal implants are monoaxial bone screws with aspherical external shape.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have at least one slot.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have at multiple slots.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature and a chamferor taper.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature that causes atleast a portion of the outside surface of the spinal implant to moveoutward.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature where thelocking feature is a set screw having a section of the set screw with achamfer or taper.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature where thelocking feature is a set screw having a section of the set screw with achamfer or taper, the set screw chamfer or taper engaging a chamfer ortaper in the spinal implant, such that tightening the set screw causesat least a portion of the spinal implant body to flair outward.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature that is a setscrew where the bottom of the set screw contacts an inside surface ofthe spinal implant such that tightening the set screw causes at least aportion of the spinal implant body to flair outward.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature that is a cam,whereby turning the cam causes at least a portion of the spinal implantbody to flair outward.

The present invention provides for a plate for attachment to spinalimplants where the spinal implants have a locking feature that isself-contained within the spinal implant.

The present invention provides for a plate for attachment to spinalimplants, the plate having the ability to adjust for different distancesbetween two spinal implants.

The present invention provides for a plate for attachment to spinalimplants where the amount of adjustment for different distances betweentwo spinal implants can be increased as the plate length is increased.

The present invention provides for a plate for attachment to spinalimplants where the plate has the ability to adjust and compensate fordifferences in angulation between two spinal implants.

The present invention provides for a plate for attachment to spinalimplants where the plate has the ability to adjust and compensate fordifferences in angulation between two spinal implants and the ability toadjust for different distances between two spinal implants.

The present invention provides for a series of plates for attachment tospinal implants where the plate has the ability to adjust and compensatefor differences in angulation between two spinal implants and theability to adjust for different distances between two spinal implants.

The present invention provides for a plate for attachment to spinalimplants where the plate has the ability to adjust and compensate fordifferences in angulation between two spinal implants by attaching to apolyaxial screw assembly, the polyaxial assembly including a bone screwwith a head, a polyaxial screw body and an insert that connects to androtates about the bone screw head.

The present invention provides for a plate for attachment to spinalimplants where the plate has the ability to adjust and compensate fordifferences in angulation between two spinal implants by attaching to apolyaxial screw assembly, the polyaxial assembly including a bone screwwith a head, a polyaxial screw body and an insert that connects to androtates about the bone screw head, where the angulation of the plate canbe locked by locking the polyaxial assembly, thereby tightening theinsert against the bone screw head.

The present invention provides for a plate for attachment to spinalimplants where the plate has the ability to adjust and compensate fordifferences in angulation between two spinal implants by attaching to apolyaxial screw assembly, the polyaxial assembly including a bone screwwith a head, a polyaxial screw body and an insert such that the bonescrew and head can be attached to the bone first and the polyaxial screwbody and insert snapped over the bone screw head prior to attaching theplate.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing that can rotate within the opening in the plate.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing that can rotate within the opening in the platewhere the plate is contoured to match the curvature of the spine.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing that can rotate within the opening in the plate, theplate opening being shaped to retain the spherical bearing.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing that can rotate within the opening in the plate, theplate opening having at least a partially spherically surface to retainthe spherical bearing.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing that can rotate within the opening in the plate, theplate opening having a shape other than spherical, such as a cylinderwith two internal rings or chamfers to retain the spherical bearing.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing andthe spherical bearing can be pressed into the opening in the plate.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing, the spherical bearing having at least one slot toallow the bearing to flex inward.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing having multiple slots to allow the bearing to flexinward.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing having multiple slots to allow the bearing to flexinward, and the slots are of uniform height and width.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing having multiple slots to allow the bearing to flexinward, and the slots are of varying height and/or width.

The present invention provides for a plate for attachment to spinalimplants whereby the plate contains an opening for a spherical bearingand a spherical bearing where the spherical bearing is a section of asphere and has a diameter and a length.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing being a section of a sphere and having a diameterand a length and an inner opening.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing being a section of a sphere and having a diameterand a length and an inner opening, the inner opening being a cylindricalbore for accepting a spinal implant.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing being a section of a sphere and having a diameterand a length and an inner opening, the inner opening being a cylindricalbore having additional features, such as a step, for attaching to aspinal implant.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing being a section of a sphere and having a diameterand a length and an inner opening, the inner opening not beingcylindrical and another shape, such as square, hexagonal, or othershape, optionally having additional features, such as a step, forattaching to a spinal implant.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing having a smooth external surface.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing,the spherical bearing having an external surface that is textured orroughened by a machining, forming, or finishing process.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening for a spherical bearing anda spherical bearing having an external surface that is textured bymachining a series of grooves into the surface of the bearing.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting aspinal implant therewithin.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting aspinal implant therewithin such that a portion of the inside surface ofthe plate oblong opening contacts or can be forced to contact the spinalimplant when the spinal implant is locked to the plate.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting aspinal implant therewithin and a spinal implant has a groove in the sidesuch that a portion of the inside surface of the plate oblong openingfits within the groove in the side of the spinal implant.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting aspinal implant therewithin and a spinal implant has a groove in the sidesuch that a portion of the inside surface of the plate oblong openingfits within the groove in the side of the spinal implant and the spinalimplant can slide within the oblong opening.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting asliding component therewithin.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting asliding component therewithin, the oblong opening having a recessedpocket to accept a sliding component.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting asliding component therewithin, the oblong opening having walls of theopening or a recessed pocket that is smooth.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting asliding component therewithin, the oblong opening whereby the walls ofthe opening or recessed pocket is textured.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting asliding component therewithin, the oblong opening having a length thatis longer than the length of the sliding component.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an oblong opening for accepting asliding component therewithin, the sliding component having an openingfor accepting a spinal implant.

The present invention provides for a sliding component having an openingfor accepting a spinal implant and at least one slot such that slidingcomponent can contract and expand.

The present invention provides for a sliding component having an openingfor accepting a spinal implant and at least one slot such that thesliding component can contract such that it can be pushed into theoblong opening in the plate and subsequently expanded so it can beretained in the plate.

The present invention provides for a sliding component shaped to fitwithin a recess in the plate.

The present invention provides for a sliding component shaped to fitwithin a recess in the plate while having a portion above and/or belowthe plate.

The present invention provides for a sliding component within an openingin a plate or other connector, the sliding component having an openingfor accepting a spinal implant and at least one slot such that thesliding component can be forced outward by locking of the spinal implantsuch that at least a portion of the external wall of the slider isforced to engage at least a portion of the inside of the opening of theplate or connector.

The present invention provides for a sliding component within an openingin a plate or other connector, the sliding component having an openingfor accepting a spinal implant and at least one slot such that thesliding component can be forced outward by locking of the spinal implantsuch that at least a portion of the external wall of the slider isforced to engage at least a portion of the inside of the opening of theplate or connector, effectively locking the position of the sliderrelative to the plate or connector.

The present invention provides for a sliding component within an openingin a plate or other connector, the sliding component having an openingfor accepting a spherical bearing.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening to accept a sphericalbearing or spinal implant with a spherical surface and an oblong openingfor accepting a spinal implant therewithin such that the angle andlength of the plate can be rigidly locked.

The present invention provides for a plate for attachment to spinalimplants where the plate contains an opening to accept a sphericalbearing or spinal implant with a spherical surface and an oblong openingfor accepting a spinal implant therewithin and a section of the platethat can be contoured or bent to allow adjustment of the curvature ofthe plate.

The present invention provides for a plate construct for attachment tospinal implants, the plate construct containing an opening to accept aspherical bearing or spinal implant with a spherical surface and anoblong opening for accepting a slider and a spinal implant therewithinsuch that the angle and length of the plate can be rigidly locked.

The present invention provides for a plate construct for attachment tospinal implants, the plate construct connecting a first implant and asecond implant, and an additional plate construct can be connected tothe first or second spinal implant in the first construct andsubsequently connected to a third implant to treat multiple level spinedisorders.

The present invention provides for a plate construct for attachment tospinal implants, the plate construct connecting a first implant and asecond implant, and an additional plate construct can be connected tothe first or second spinal implant in the first construct andsubsequently connected to a third implant to treat multiple level spinedisorders, and additional plate constructs added as necessary to treatas many spinal levels as required.

The present invention provides for a plate construct for attachment tospinal implants, the plate construct connecting a short first implantand a taller second implant such that the second spinal implant is tallenough to accept an additional plate construct.

The present invention provides for a plate construct for attachment tospinal implants where multiple plate constructs can connect as manyshort implants and tall implants as needed to span the necessary levelsin the spine.

The present invention provides for a plate construct for attachment tospinal implants where the spinal implants are attached to the pediclesfirst and the plate construct is placed over the spinal implants andsecured to the spinal implants.

The present invention provides for a plate having a contourable section.

The present invention provides for a plate having a contourable sectionthat is rectangular, square, round, half round, or any other geometriccross-section.

The present invention provides for combining the benefits of a platingsystem with the benefits of a rod system.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a spinal fixation device includes atleast one bone screw, at least one locking nut, a bearing, at least oneslider, and an elongate plate construct. The bone screw has a head witha nut connection section and a screw portion shaped to screw into bone.The locking nut has an internal bore shaped to connect to the nutconnection section of the at least one bone screw and an exterior wall.The bearing has an exterior and defining an internal bore shaped to fittherein the nut connection section of the head and the exterior wall ofthe at least one locking nut. The slider defines an internal bore shapedto fit the exterior wall of the at least one locking nut therewithin andhas an exterior with a given shape. The elongate plate construct has afirst end defining a first opening shaped to accept the exterior of thebearing therein and a second end defining a second opening shaped toaccept the at least one slider therein and having a corresponding shapeto the given shape to permit the at least one slider to slide in atleast a portion of the second opening.

With the objects of the invention in view, there is also provided abearing for a modular spinal fixation assembly having a plate construct,a bone screw with a nut connection section, and a locking nut with anexterior wall, the bearing comprising a spherical bearing body. The bodydefines an internal bore having an upper, outwardly chamfered surface,having an intermediate cylindrical surface, having a lower, outwardlychamfered surface, and shaped to fit therein the nut connection sectionof the bone screw and the exterior wall of the locking nut. The body hasa circumference, an outer surface, a top face, a bottom face and atleast one slot extending from each of the top and bottom faces towardsthe other one of the top and bottom faces and extending in depth fromthe internal bore to the outer surface. When connected to the plateconstruct between the bone screw and the locking nut, further clampingof the bone screw and the locking nut together expands the bearingevenly along the circumference.

With the objects of the invention in view, there is also provided amodular spinal fixation assembly includes at least two bone screws, atleast two locking nuts, at least two bearings, at least one slider,first and second elongate plate constructs, and an elongate plateconnector. A first of the bone screws has a head with a nut connectionsection with a cylindrical section and a screw portion shaped to screwinto bone. A second of the bone screws has a head with a nut connectionsection with an extended cylindrical section and a screw portion shapedto screw into bone. The two locking nuts each has an internal boreshaped to connect to the nut connection section of each of the at leasttwo bone screws and an exterior wall. The two bearings each have anexterior and define an internal bore shaped to fit therein the nutconnection section of the head of the first and second bone screws andthe exterior wall of each of the at least two locking nuts. The sliderdefines an internal bore shaped to fit the exterior wall of the at leastone locking nut therewithin and has an exterior with a given shape. Thefirst and second elongate plate constructs each have a first enddefining a first opening shaped to accept the exterior of one of the atleast two bearings therein and a second end defining a second openingshaped to accept the at least one slider therein and having acorresponding shape to the given shape to permit the at least one sliderto slide in at least a portion of the second opening The elongate plateconnector has a first end with a locking nut connection section shapedto connect to the internal bore of one of the locking nuts and has asecond end defining a bore shaped to accept therein an exterior of theextended cylindrical section of the nut connection section of the secondbone screw, and connects the first and second elongate plate constructstogether with a first of the at least two locking nuts attached to thelocking nut connection section and surrounded by a first of the at leasttwo bearings within the first opening of the first end of the firstelongate plate construct, and a second of the at least two locking nutsattached to the nut connection section of the second bone screw andsurrounded by a second of the at least two bearings within the firstopening of the first end of the second elongate plate construct, theextended cylindrical section of the second bone screw being disposedwithin the bore of the second end of the elongate plate connector.

When the bearing is placed within the first opening, and the head of theat least one bone screw is placed through the internal bore of thebearing, and the at least one locking nut is attached to the nutconnection section to secure the bone screw head, the bearing, and theat least one locking nut therein, the bearing permits the bone screwhead to move within the first opening relative to the elongate plateconstruct.

In accordance with another feature of the invention, when the head ofthe at least one bone screw is placed within the internal bore of the atleast one slider, and the at least one slider is placed slidably in thesecond opening of the elongate plate construct, and the at least onelocking nut is attached to the nut connection section through theinternal bore, the at least one slider permits the bone screw to moveand slide within the second opening relative to the elongate plateconstruct.

In accordance with a further feature of the invention, the nutconnection section includes a threaded portion, a non-threaded portionnext to the threaded portion opposite the screw portion, a cylindricalsection, a recess between the cylindrical section and the threadedportion, and a tapered section between the cylindrical section and thescrew portion.

In accordance with an added feature of the invention, the internal boreof the at least one locking nut releasably connects to the nutconnection section of the at least one bone screw.

In accordance with an additional feature of the invention, the at leastone locking nut has features shaped to connect to a tool that removablyconnects the at least one locking nut to the nut connection section ofthe at least one bone screw.

In accordance with yet another feature of the invention, the exterior ofthe bearing is spherical in shape and the internal bore of the bearinghas an upper, outwardly chamfered surface, an intermediate cylindricalsurface, and a lower, outwardly chamfered surface.

In accordance with yet a further feature of the invention, the exteriorwall of the at least one locking nut has a given outer diameter, the atleast one locking nut has interior threads shaped to mate with theexterior threads of the nut connection section, a head with a headdiameter greater than the given outer diameter, a lower lip with a lipdiameter greater than the given outer diameter, and a lower-facing,chamfered surface tapering from the head at the head diameter to theexterior wall at the given outer diameter, the exterior wall beingdisposed between the lower lip and the upper chamfered surface, and thenut connection section of the at least one bone screw has exteriorthreads and an expanded section between the exterior threads and thescrew portion and wider in diameter than the exterior threads and thescrew portion and having an upper chamfered surface tapering inwards andupwards from a larger outer diameter to a smaller inner diameter.

In accordance with yet an added feature of the invention, when the headof the at least one bone screw is placed through the internal bore ofthe bearing and the at least one locking nut is attached to the nutconnection section to secure the bearing between the upper chamferedsurface of the at least one bone screw and the lower-facing, chamferedsurface of the at least one locking nut, the bearing expands at theupper, outwardly chamfered surface and the lower, outwardly chamferedsurface circumferentially as the at least one locking nut is tightenedonto the exterior threads.

In accordance with yet an additional feature of the invention, thebearing has a top face, a bottom face, and at least one slot extendingfrom one of the top and bottom faces towards the other one of the topand bottom faces.

In accordance with again another feature of the invention, the at leastone slot is at least one of at least one slot extending from each of thetop and bottom faces and slots extending from each of the top and bottomfaces.

In accordance with again a further feature of the invention, theinternal bore of the bearing is shaped to fit therein both the nutconnection section of the head and the exterior wall of the at least onelocking nut.

In accordance with again an added feature of the invention, the slideris a slider assembly with a top sliding component having a bore shapedto accommodate therein the exterior wall of the at least one locking nutand being disposed on a side of the elongate plate construct oppositethe screw portion of the at least bone screw and a bottom slidingcomponent having a bore shaped to accommodate therein the exterior wallof the at least one locking nut and being disposed on a side of theelongate plate construct opposite the top sliding component.

In accordance with again an additional feature of the invention, theslider assembly includes a top washer having a bore shaped toaccommodate therein the exterior wall of the at least one locking nutand being disposed between the at least one locking nut and the topsliding component, when the head of the at least one bone screw isplaced within the bore of the bottom sliding component, the bore of thetop sliding component, and the bore of the top washer, and the at leastone locking nut is partially tightened to the nut connection section,the top washer and the top sliding component permit the bone screw tomove and slide within the second opening relative to the elongate plateconstruct, and when the head of the at least one bone screw is placedwithin the bore of the bottom sliding component, the bore of the topsliding component, and the bore of the top washer, and the at least onelocking nut is fully tightened to the nut connection section, the topwasher and the top sliding component prevent the bone screw from movingor sliding within the second opening relative to the elongate plateconstruct.

In accordance with still another feature of the invention, the firstopening is shaped to accept the bone screw head, the bearing, and the atleast one locking nut therein and the second opening is shaped to acceptthe bone screw head, the bearing, and the at least one slider therein.

In accordance with still a further feature of the invention, the firstopening is shaped to allow pitch, roll, and yaw movement of the bearingtherein.

In accordance with still an added feature of the invention, when thebearing is placed within the first opening, and the head of the at leastone bone screw is placed through the internal bore of the bearing, andthe at least one locking nut is removably attached to the nut connectionsection to secure the bone screw head, the bearing, and the at least onelocking nut therein, the bearing permits the bone screw head to at leastpartially roll, pitch, and yaw within the first opening relative to theelongate plate construct.

In accordance with still an additional feature of the invention, whenthe head of the at least one bone screw is placed within the internalbore of the at least one slider, and the at least one slider is placedslidably in the second opening of the elongate plate construct, and theat least one locking nut is removably attached to the nut connectionsection through the internal bore, the at least one slider permits thebone screw to rock and slide within the second opening relative to theelongate plate construct.

In accordance with another feature of the invention, the elongate plateconstruct has a rod portion connecting the first end to the second end.

In accordance with a further feature of the invention, the first end isplate shaped and the second end is plate shaped.

In accordance with an added feature of the invention, the bearing is twobearings, both having a given longitudinal length through the bore, theelongate plate construct is at least first and second elongate plateconstructs, at least one locking nut has internal threads and connectsthe first and second elongate plate constructs together at therespective first ends by placing the two bearings one on top of theother on the nut connection section and tightening the internal threadsof the extended locking nut onto the threaded portion of the at leastone bone screw, and an overall length of at least one of the nutconnection section of the at least one bone screw and the at least onelocking nut is at least twice as long as the given longitudinal length.

In accordance with an additional feature of the invention, the at leastone bone screw is at least two bone screws, a first of the at least twobone screws having the nut connection section with a cylindrical sectionand the second of the at least two bone screws having the nut connectionsection with an extended cylindrical section, the at least one lockingnut is at least two locking nuts, the bearing is at least two bearings,the elongate plate construct is at least first and second elongate plateconstructs, and further comprising an elongate plate connector having afirst end with a locking nut connection section shaped to connect to theinternal bore of one of the locking nuts, having a second end defining abore shaped to accept therein an exterior of the extended cylindricalsection of the nut connection section of the second bone screw, andconnecting the first and second elongate plate constructs together witha first of the at least two locking nuts attached to the locking nutconnection section and surrounded by a first of the at least twobearings within the first opening of the first end of the first elongateplate construct, and a second of the at least two locking nuts attachedto the nut connection section of the second bone screw and surrounded bya second of the at least two bearings within the first opening of thefirst end of the second elongate plate construct, the extendedcylindrical section of the second bone screw being disposed within thebore of the second end of the elongate plate connector.

In accordance with yet another feature of the invention, when theexterior of the extended cylindrical section of the nut connectionsection of the second bone screw is place through the bore of the secondend of the elongate plate connector, and the head of the second bonescrew is placed through the internal bore of one of the bearings, andthe one of the bearings and the head of the second bone screw are placedwithin the first opening of the first plate construct, and one of thelocking nuts is attached to the locking nut connection section to securethe head of the second bone screw, the one of the bearings, and the onelocking nut therein, the one bearing permits the bone screw head to movewithin the first opening relative to the first plate construct.

In accordance with yet a further feature of the invention, when the headof the first bone screw is placed within the internal bore of the atleast one slider, and the at least one slider is placed slidably in thesecond opening of one of the first and second elongate plate constructs,and one of the locking nuts is attached to the nut connection section ofthe first bone screw through the internal bore of the at least oneslider, the at least one slider permits the bone screw to move and slidewithin the second opening relative to the one of the first and secondplate constructs.

In accordance with yet an added feature of the invention, the plateconnector removably connects the first and second elongate plateconstructs together.

In accordance with yet an additional feature of the invention, theextended cylindrical section of the second bone screw is rotatablydisposed within the bore of the second end of the elongate plateconnector.

In accordance with again another feature of the invention, the firstopening is shaped to accept the bone screw head, the bearing, and the atleast one locking nut therein and the second opening is shaped to acceptthe bone screw head, the bearing, and the at least one slider therein.

In accordance with a concomitant feature of the invention, the firstopening is shaped to allow pitch, roll, and yaw movement of the bearingtherein.

Although the invention is illustrated and described herein as embodiedin a polyaxial plate rod system and surgical procedures for insertion ofthe polyaxial plate rod system, it is, nevertheless, not intended to belimited to the details shown because various modifications andstructural changes may be made therein without departing from the spiritof the invention and within the scope and range of equivalents of theclaims. Additionally, well-known elements of exemplary embodiments ofthe invention will not be described in detail or will be omitted so asnot to obscure the relevant details of the invention.

Additional advantages and other features characteristic of the presentinvention will be set forth in the detailed description that follows andmay be apparent from the detailed description or may be learned bypractice of exemplary embodiments of the invention. Still otheradvantages of the invention may be realized by any of theinstrumentalities, methods, or combinations particularly pointed out inthe claims.

Other features that are considered as characteristic for the inventionare set forth in the appended claims. As required, detailed embodimentsof the present invention are disclosed herein; however, it is to beunderstood that the disclosed embodiments are merely exemplary of theinvention, which can be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one of ordinary skill in the art tovariously employ the present invention in virtually any appropriatelydetailed structure. Further, the terms and phrases used herein are notintended to be limiting; but rather, to provide an understandabledescription of the invention. While the specification concludes withclaims defining the features of the invention that are regarded asnovel, it is believed that the invention will be better understood froma consideration of the following description in conjunction with thedrawing figures, in which like reference numerals are carried forward.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures, where like reference numerals refer toidentical or functionally similar elements throughout the separateviews, which are not true to scale, and which, together with thedetailed description below, are incorporated in and form part of thespecification, serve to illustrate further various embodiments and toexplain various principles and advantages all in accordance with thepresent invention. Advantages of embodiments of the present inventionwill be apparent from the following detailed description of theexemplary embodiments thereof, which description should be considered inconjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of an exemplary embodiment of a plateassembly with polyaxial screws;

FIG. 2 is a perspective view of an exemplary embodiment of a bone screwof the plate assembly of FIG. 1;

FIG. 3 is an exploded perspective view of an exemplary embodiment of apolyaxial body of the plate assembly of FIG. 1 aligned with a bone screwhead;

FIG. 4 is a cross-sectional view of the polyaxial body of the plateassembly of FIG. 1;

FIG. 5 is a perspective view of the polyaxial insert of the plateassembly of FIG. 1 from a side thereof;

FIG. 6 is a perspective view of the polyaxial insert of the plateassembly of FIG. 1 from a bottom thereof;

FIG. 7 is a side elevational view of an exemplary embodiment of a setscrew of the plate assembly of FIG. 1;

FIG. 8 is a perspective view of the set screw of FIG. 7 from above;

FIG. 9 is a partially cross-sectional, perspective view of an exemplaryembodiment of a polyaxial assembly of the plate assembly of FIG. 1 in anunlocked position;

FIG. 10 is partially cross-sectional, perspective view of the polyaxialassembly of the plate assembly of FIG. 1 in a locked position;

FIG. 11 is a perspective view of an exemplary embodiment of a monoaxialor fixed screw;

FIG. 12 is a perspective view of the monoaxial or fixed screw of FIG. 11from above;

FIG. 13 is a top plan view of an exemplary embodiment of a plate of theplate assembly of FIG. 1;

FIG. 14 is a perspective view of the plate of FIG. 13 from above;

FIG. 15 is a cross-sectional view of the plate of FIG. 13;

FIG. 16 is a perspective view of an exemplary embodiment of a slider ofthe plate assembly of FIG. 1;

FIG. 17 is a side elevational view of the slider of FIG. 16;

FIG. 18 is a perspective view of an exemplary embodiment of a sphericalbearing for the plate assembly of FIG. 21;

FIG. 19 is a top plan view of the spherical bearing of FIG. 18;

FIG. 20 is a perspective view of another exemplary embodiment of aspherical bearing for the plate assembly of FIG. 21;

FIG. 21 is a perspective view of another exemplary embodiment of a plateassembly;

FIG. 22 is a perspective view of an exemplary embodiment of a plate ofthe plate assembly of FIG. 21;

FIG. 23 is a top plan view of the plate of FIG. 22;

FIG. 24 is a perspective view of an exemplary embodiment of a slider ofthe plate assembly of FIG. 21 from above;

FIG. 25 is perspective view of the slider of FIG. 24 from a sidethereof;

FIG. 26 is a perspective view of the plate assembly of FIGS. 22 to 25placed above monoaxial screws;

FIG. 27 is a perspective view of the plate assembly of FIG. 26 partiallyengaged with the monoaxial screws;

FIG. 28 is a perspective view of the plate assembly of FIG. 26 fullyengaged with the monoaxial screws;

FIG. 29 is a perspective view of an exemplary embodiment of a fixedscrew with a spherical head;

FIG. 30 is a perspective view of the fixed screw of FIG. 29 from above;

FIG. 31 is a perspective view of a further exemplary embodiment of aplate for the plate assembly of FIG. 33;

FIG. 32 is a perspective view of another exemplary embodiment of a screwbody for the plate of FIG. 31;

FIG. 33 is a perspective view of an exemplary embodiment of a dual levelconstruct with the plate of FIG. 31;

FIG. 34 is a perspective view of an exemplary embodiment of a dual levelconstruct with the plate of FIG. 1;

FIG. 35 is a perspective view of an exemplary embodiment of an offsetplate dual level construct with the plate of FIG. 1;

FIG. 36 is a perspective view of the bottom the offset plate of FIG. 35;

FIG. 37 is a side elevational view of the offset plate of FIG. 35;

FIG. 38 is a perspective view of exemplary embodiments of a plateassembly, a set screw driver, and a counter torque-screwdriver;

FIG. 39 is a perspective view of a tip of the counter torque-screwdriverof FIG. 38;

FIG. 40 is a perspective view of the tip of the countertorque-screwdriver of FIG. 38 engaging an assembly;

FIG. 41 is a perspective view of the tip of the set screw driver of FIG.38 engaging an assembly;

FIG. 42 is a perspective view of an exemplary embodiment of a plate rodconstruct having a round or semi-round center section and an alternativesphere and slider mechanism;

FIG. 43 is an elevational view of an exemplary embodiment of a bonescrew, such as the bone screw in FIG. 42;

FIG. 44 is a perspective view of the bone screw of FIG. 43;

FIG. 45 is a perspective view of an exemplary embodiment of a sphericalbearing;

FIG. 46 is a fragmentary, side elevational view of the spherical bearingof FIG. 45 in a plate or rod end;

FIG. 47 is a fragmentary, side elevational view of the spherical bearingof FIG. 46 with the bearing rotated;

FIG. 48 is a fragmentary, cross-sectional view of the bearing housing inthe plate or rod end of FIGS. 46 and 47;

FIG. 49 is a fragmentary, cross-sectional view of the bearing andbearing housing of FIG. 46;

FIG. 50 is a fragmentary, cross-sectional view of the bearing and thebearing housing of FIG. 47 with the bearing rotated;

FIG. 51 is an perspective view of an exemplary embodiment of a lockingnut;

FIG. 52 is a side elevational view of the locking nut of FIG. 51;

FIG. 53 is a perspective view of an exemplary embodiment of a taperedcollar or ring;

FIG. 54 is an exploded view of an exemplary embodiment of a plate-rodconstruct assembly;

FIG. 55 is an exploded perspective view of an exemplary embodiment of aslider assembly;

FIG. 56 is an exploded side elevational view of the slider top andbottom washers;

FIG. 57 is a, fragmentary, exploded, perspective view of an exemplaryembodiment of a slider and a plate/rod end assembly;

FIG. 58 is a fragmentary, perspective view of an assembly with anexemplary embodiment of a slider variation allowing bone screw rotation;

FIG. 59 is an exploded perspective view of the slider variation of FIG.58;

FIG. 60 is a perspective view of the lower sliding component of theassembly of FIG. 58;

FIG. 61 is a cross-sectional view of the lower sliding component of theassembly of FIG. 58;

FIG. 62 is a perspective view of the upper sliding component of theassembly of FIG. 58;

FIG. 63 is a side elevational view of the upper sliding component of theassembly of FIG. 58;

FIG. 64 is a perspective view of an exemplary embodiment of a washer ofthe assembly of FIG. 59;

FIG. 65 is a fragmentary, side elevational view of an exemplaryembodiment of a slider with the assembly in a partially rotatedposition;

FIG. 66 is a fragmentary, cross-sectional view of the slider of FIG. 65with the assembly shown in a partially rotated position;

FIG. 67 is an enlarged view of a bone screw with an arcuate bone screwface.

FIG. 68 is a fragmentary, cross-sectional view of the slider assembly ofFIG. 65 with the arcuate face bone screw of FIG. 67;

FIG. 68A is a cross-sectional view of an exemplary embodiment of aslider assembly;

FIG. 69 is a fragmentary, exploded perspective view of an exemplaryembodiment of a slider assembly;

FIG. 70 is a perspective view of an exemplary embodiment of a sliderblock of the assembly of FIG. 69;

FIG. 71 is a cross-sectional view of the slider block of FIG. 69;

FIG. 72 is a fragmentary, perspective view of the slider assembly ofFIG. 69 without the bone screw;

FIG. 73 is a fragmentary, cross-sectional view of the slider assembly ofFIG. 72 with the bone screw;

FIG. 74 is a fragmentary, exploded, perspective view of anotherexemplary embodiment of a slider assembly that allows rotation;

FIG. 75 is a perspective view of a top washer of the assembly of FIG.74;

FIG. 76 is a perspective view of a pivot sliding component of theassembly of FIG. 74;

FIG. 77 is a fragmentary, perspective view of the plate or rod end ofthe assembly of FIG. 74;

FIG. 78 is a perspective view of a lower bearing or pivot of theassembly of FIG. 74;

FIG. 79 is a fragmentary, side elevational view of the slider assemblyof FIG. 74 with the screw locked at an angle;

FIG. 80 is a fragmentary, exploded perspective view of an exemplaryembodiment of a slider assembly that allows rotation;

FIG. 81 is a perspective view of a rotation block of the assembly ofFIG. 80;

FIG. 82 is a fragmentary, side elevational view of the assembly of FIG.80 with the screw locked at an angle;

FIG. 83 is a fragmentary, exploded, perspective view of an exemplaryembodiment of a slider assembly that allows polyaxial rotation;

FIG. 84 is a cross-sectional view of a polyaxial body component of theassembly of FIG. 83;

FIG. 85 is a cross-sectional view of a lower sliding component of theassembly of FIG. 83;

FIG. 86 is a fragmentary, cross-sectional view of the polyaxial assemblyof FIG. 83;

FIG. 87 is a perspective view of an exemplary embodiment of a two levelconnector from above;

FIG. 88 is a perspective view of the two level connector of FIG. 87 frombelow;

FIG. 89 is a fragmentary, exploded, perspective view of a partialassembly of the two level connector of FIG. 87 from a side thereof;

FIG. 90 is a fragmentary, exploded, perspective view of the two levelconnector assembly of FIG. 87 from above;

FIG. 91 is a perspective view of an exemplary embodiment of a two levelconstruct assembly; and

FIG. 92 is a perspective view of an exemplary embodiment of acompressor/distracter instrument.

DETAILED DESCRIPTION OF THE INVENTION

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which can be embodied in variousforms. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the present invention in virtually anyappropriately detailed structure. Further, the terms and phrases usedherein are not intended to be limiting; but rather, to provide anunderstandable description of the invention. While the specificationconcludes with claims defining the features of the invention that areregarded as novel, it is believed that the invention will be betterunderstood from a consideration of the following description inconjunction with the drawing figures, in which like reference numeralsare carried forward.

Alternate embodiments may be devised without departing from the spiritor the scope of the invention. Additionally, well-known elements ofexemplary embodiments of the invention will not be described in detailor will be omitted so as not to obscure the relevant details of theinvention.

Before the present invention is disclosed and described, it is to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting. The terms “a” or “an”, as used herein, are defined as one ormore than one. The term “plurality,” as used herein, is defined as twoor more than two. The term “another,” as used herein, is defined as atleast a second or more. The terms “including” and/or “having,” as usedherein, are defined as comprising (i.e., open language). The term“coupled,” as used herein, is defined as connected, although notnecessarily directly, and not necessarily mechanically.

Relational terms such as first and second, top and bottom, and the likemay be used solely to distinguish one entity or action from anotherentity or action without necessarily requiring or implying any actualsuch relationship or order between such entities or actions. The terms“comprises,” “comprising,” or any other variation thereof are intendedto cover a non-exclusive inclusion, such that a process, method,article, or apparatus that comprises a list of elements does not includeonly those elements but may include other elements not expressly listedor inherent to such process, method, article, or apparatus. An elementproceeded by “comprises . . . a” does not, without more constraints,preclude the existence of additional identical elements in the process,method, article, or apparatus that comprises the element.

As used herein, the term “about” or “approximately” applies to allnumeric values, whether or not explicitly indicated. These termsgenerally refer to a range of numbers that one of skill in the art wouldconsider equivalent to the recited values (i.e., having the samefunction or result). In many instances these terms may include numbersthat are rounded to the nearest significant figure.

Herein various embodiments of the present invention are described. Inmany of the different embodiments, features are similar. Therefore, toavoid redundancy, repetitive description of these similar features maynot be made in some circumstances. It shall be understood, however, thatdescription of a first-appearing feature applies to the later describedsimilar feature and each respective description, therefore, is to beincorporated therein without such repetition.

Described now are exemplary embodiments of the present invention.Referring now to the figures of the drawings in detail, there is shown afirst exemplary embodiment of a new implant assembly illustratedgenerally at 100 in FIGS. 1 through 10, that, by its novel construction,permits the implant 100 to attach to bone screws while compensating foranatomic considerations and breaking down complex multilevel surgicalprocedures into simpler single level procedures.

Plate 1 is substantially rectangular in shape. Of course, the plate 1does not need to be rectangular, but can also be other shapes. Plate 1,as well as the other components of the implant can be made of variousmaterials, such as, but not limited to, metals, such as titanium, orstainless steels, polymers, or a combination of both.

The assembly 100 has various features as shown in FIG. 1. These featuresinclude the plate 1, a slider component 2, a spherical or partiallyspherical bearing 3 (see, e.g., FIGS. 18 and 19), a bone screw 6 forengagement with a bone, a polyaxial screw body 7, and a set screw 9.

FIG. 2 details a version of the bone screw 6. The bone screw 6 has athreaded portion 6 a having a tip 6 b, a spherical head 6 c, a top ofthe spherical section 6 d, a driving feature 6 e for turning andadvancing or removing the screw from the bone, a neck portion 6 fbetween the spherical head 6 c and threads 6 a, and blend radii 6 g toblend the neck 6 f into the spherical head 6 c to avoid any sharptransitions. The bone screw 6 is designed to engage bone, and, in thelumbar spine, a wall of the pedicles. The thread 6 a can be anyappropriate thread to engage bone, and the minor diameter can bestraight or tapered. Also, the spherical head 6 c can be textured orsmooth. While the screw driving feature 6 e is shown as a hex for anAllen key type driver, this feature can be one of many different kinds,including a square drive, a star drive, torx, and others.

FIG. 3 shows the bone screw 6 and head 6 c as well as a polyaxial screwbody 7 and set screw 9. In this exemplary embodiment, the polyaxialscrew body 7 can be securely attached to the bone screw head 6 c,details of which follow in the figures. The polyaxial screw body 7includes a top 7 a and a bottom surface 7 b. The polyaxial screw body 7has a recessed portion 7 c, at least one slot 7 d through a wall of thepolyaxial screw body 7, a blend radius 7 e to avoid any sharp edges thatmight impinge soft tissue, and a blend radius 7 f to avoid impingementwith soft tissue and bone. The recess 7 c creates an upper surface 7 jand a lower surface 7 h. In this example, the polyaxial screw body 7 isgenerally cylindrical and has a lower diameter 7 k. To create a largerlower and/or upper lip, the body diameter can be increased above thelower diameter 7 k, allowing a larger diameter lip 7 m withoutincreasing the depth of the recess 7 c. When this extended lip 7 m ispresented, it is preferable to have a blend radius 7 g to avoid anystress risers. The polyaxial body 7 can be cylindrical without thechanges in diameter; however, in general, having the smallest possiblediameter where the lower portion of the body will potentially contactbone is a benefit.

FIG. 4 details the inside of a polyaxial screw body 7. The section viewshows the polyaxial screw body 7 having the top 7 a and a threadedsection 7 t extending downward towards the lower surface 7 b andextending into a recess or pocket 7 m. The recess or pocket 7 mtransitions to a smaller diameter by an inwardly directed chamfer 7 p,and a longer chamfer or taper 7 n, which then transitions to opening 7 qin the polyaxial screw body 7. The screw thread in this example has achamfer or taper 7 s at the top of thread 7 k. The thread 7 k can be cutinto the chamfer or taper 7 s, as shown, or the chamfer or taper 7 s canbe partially cut into or large enough where the threads do not cut intothe taper or chamfer 7 s feature. To allow the polyaxial screw body 7 tobe flexible, at least one slot 7 d is cut into the polyaxial screw body7. The depth of slot 7 d can be varied according to requirements. Ifthere are multiple slots 7 d, the depths of the slots 7 d can also varyto better distribute stresses and/or vary flexibility of the polyaxialscrew body 7.

FIGS. 5 and 6 show a polyaxial insert 15 having a top surface 15 a and abottom surface 15 b, an external wall 15 c generally cylindrical inshape, a chamfered or tapered portion 15 d, a spherical or partiallyspherical internal feature 15 e, an opening 15 f extending into thespherical feature 15 e, a slot 15 g in the wall 15 c to provideflexibility to the polyaxial screw insert 15 so that the insert 15 canbe compressed to fit within the polyaxial screw body 7, and additionalslots 15 h to provide further flexibility. Slots 15 h are optional, asare the quantity used, and the height of the slots 15 h can vary. Theslot 15 j opposite the main slot 15 g can partially penetrate the topsurface 15 a of the polyaxial insert 15 or the top surface 15 a of theinsert 15 can be formed or machined such that the wall thickness of theinsert 15 is thinner in the location of slot 15 j to allow the polyaxialinsert 15 to flex more easily for insertion into the polyaxial screwbody 7.

FIGS. 7 and 8 show a variation of the set screw 9 having a top 9 a, atip 9 e, a tapered portion 9 b, a neck 9 c, a threaded section 9 d, anda small lip 9 f, which helps avoid a sharp edge where the taper 9 bmeets the top 9 a. A hex drive or Allen key type drive 9 g is providedShown in FIG. 8 for turning the set screw 9. However, this feature canbe of any variety used to turn a screw, such as square drive, a stardrive, torx, or any other. A chamfer 9 h avoids sharp edges at the top 9a where the driving feature intersects and provides easier attachment toan instrument. The set screw 9 can be machined with the driving feature9 g cut to a specific depth, leaving a lower face 9 j in set screw 9.Also, a hole 9 k can be machined or drilled into set screw 9 to allow aK-wire to pass therethrough. In addition, the driving feature 9 g can becut completely through set screw 9 so that no lower face 9 j remains.Furthermore, the set screw 9 can be formed without a chamfer 9 b forcertain embodiments.

FIG. 9 shows a cross-sectional view of a polyaxial screw assembly in anunlocked condition. The polyaxial screw body 7 contains the insert 15and the set screw 9. The tapered portion of the set screw 9 is outsidethe polyaxial screw body 7 and the polyaxial insert 15 is not compressedagainst the taper 7 n in the body 7, but is contained within the pocketor recess 7 m in the polyaxial body 7. In this position, the polyaxialinsert 15 is able to expand to accept the bone screw head 6 c, such thatthe head 6 c will fit and be contained within the spherical seat 15 e inthe polyaxial insert 15. Once the bone screw head 6 c is containedwithin the polyaxial insert 15, the assembly is still free at this pointto rotate around the bone screw head 6 c.

FIG. 10 shows a cross-sectional view of the polyaxial screw assembly ina locked condition. The set screw 9 is advanced such that the tip 9 e ofthe set screw 9 contacts the polyaxial insert 15 and forces it downwardwhile the taper 9 b engages the taper or chamfer 7 s in the polyaxialscrew body 7. This contact forces the polyaxial insert 15 to becompressed around the screw head 6 c by engagement of the tapers orchamfers while forcing the upper section of body 7 to at least partiallysplay outward. While shown with the set screw 9 having taper 9 b, anon-tapered set screw can also be used, as sufficient force againstinsert 15 will cause the threads 9 d to exert an outward force againstthe polyaxial screw body threads 7 t. As screw threads create forcevectors, a portion of the force is directed outward, which can alsocause the polyaxial screw body 7 to flex outward in the desired region.Of course, set screw 9 does not have to be fully threaded, but can havea longer neck 9 c or a longer unthreaded tip 9 e.

FIGS. 11 and 12 show a variation of a bone screw whereby the head 20 sof the screw 20 is one piece or integral with the bone threads andshank. The monoaxial screw 20 includes the head 20 s having a top 20 aand a lower section 20 b transitioning into the bone screw thread 20 c.Preferably, this is machined as a single piece, but it could beassembled from two components. The monoaxial screw 20 has a tip 20 d.The head portion 20 s has an internal thread 20 e extending downwardfrom the face of the top 20 a, at least one slot 20 f, a recess 20 g, achamfer 20 h at the top of the slot or slots 20 f, and an upper lip 20 kand lower lip 20 j created by the recess 20 g. The slots 20 f preferablyend in a radius 20 n to avoid any stress risers. The depth of holehaving the thread 20 e is restricted to the larger diameter of headportion 20 s, and creates a bottom surface 20 p that may be flat, drillpoint shaped, rounded, or another shape as required. In addition, anon-illustrated hole for a k-wire can be provided that runs through thecenter of the monoaxial screw 20.

FIGS. 13 and 14 show the plate 1 in greater detail. Plate 1 has a topsurface 1 a, a first end 1 b defining an opening 1 c, a rectangularsection 1 d having an end 1 e and an edge radius 1 f, and a rectangularopening 1 g. In this preferred example, the first end 1 b is generallyround and transitions to the rectangular section 1 d via a smallermiddle section 1 k. To avoid any sharp areas or stress risers, blendradius 1 u transitions the round end 1 b into the smaller rectangularsection 1 k, and radius 1 m transitions the smaller middle section 1 kto the larger rectangular section 1 d. While the plate 1 can be machinedas a uniform rectangle, by having a smaller section 1 k, the plate canbe more easily contoured or bent to match patient anatomy when needed.The rectangular opening 1 g includes a recessed pocket with a surface 1h recessed into top surface 1 a, which creates a small side wall 1 n. Asmaller rectangular opening is machined through the plate 1, whichcreates an inwardly directed lip 1 j. The bottom of the plate has arecessed pocket 1 t larger than the smaller rectangular opening. Theedges of lip 1 j transition by blend radii 1 w, and the edges of theplate 1 have an upper blend radius 1 s and a lower radius 1 q to avoidany sharp edges that might cause tissue impingement. In this exemplaryembodiment, the opening 1 c is generally round and has a sphericallyshaped wall 1 r. It is also possible to construct the wall 1 r by theuse of two inwardly directed opposed chamfers. At least one opening 1 y,provides a location for an instrument to fit therein.

FIG. 15 is a cross-sectional view that better shows the recessedfeature. By cutting a pocket in the top 1 a of plate 1 and a pocket inthe bottom 1 p of the plate 1 and cutting a smaller rectangle throughboth pockets, the machining leaves a ledge 1 h that runs around the topof the pocket and a ledge 1 v that runs around the bottom of the pocket.This allows a sliding component 2 to fit within the pocket to have thetop 2 a of the slider 2 be flush with the top 1 a of plate 1 and thebottom 2 b of the slider 2 be flush with the bottom 1 p of plate 1. Thespherical shape of wall 1 r is also shown much clearer in this sectionalview.

FIGS. 16 and 17 show a variation of the slider 2 configured to fit intothe recessed plate 1. This exemplary slider 2 has a top surface 2 a anda lower surface 2 b, a back edge 2 c and a front edge 2 d, a hole 2 nthrough the slider 2 creates a side wall 2 e, a recess 2 f machined intothe side of the slider 2 creates an upper lip 2 g and face 2 h, a lowerlip 2 j and face 2 k, blend radii 2 m at the corners of the recess, aslot 2 p that cuts through the front edge 2 d and extends into hole 2 n,an optional additional slot 2 q that partially extends into the slider 2to increase slider flexibility, a small pocket 2 r cut into front edge 2d, and a small pocket 2 s cut into the rear edge 2 c, and a chamfer 2 tto make it easier to insert slider 2 into plate 1.

FIGS. 18 and 19 show a variation of a spherical bearing 3 having anexternal spherical surface 3 a that is either smooth or, as shown here,textured, a top edge 3 b, a bottom edge 3 c, a central hole 3 d, achamfer 3 e, and a slot 3 f which allows the spherical bearing to expandand contract.

FIG. 20 shows another variation of the spherical bearing whereby thebearing 4 has a spherical external surface 4 a, a top surface 4 b, acylindrical section 4 c, a lower edge 4 d, an internal bore 4 e, andmultiple slots 4 f that cut part way through the bearing such that thebearing is flexible but not split as in bearing 3. The slots preferablyend in radii 4 g to avoid stress risers, and the heights of the slots 4f can vary independently.

FIG. 21 shows another variation of a plate assembly, generally shown as200. In this example, monoaxial screws 20 are used as the bone anchors.Plate 30 has a spherical opening to accept a spherical bearing, shown inthis case as bearing 4, although alternatives, such as bearing 3 areacceptable, and an opening to accept an alternative slider 40. When theset screws 9 are tightened, the head of the first monoaxial screw 20 isforced outward, locking the monoaxial screw 20 to slider 40 and slider40 to plate 30, and the second monoaxial screw 20 locks to the sphericalbearing 4 and the bearing 4 to plate 30, thus locking the assembly inthe desired orientation.

FIGS. 22 and 23 show an alternative plate 30 having a top surface 30 a,a front section with a front round edge 30 b and a central hole 30 cwith an interior surface 30 r, and a rectangular section 30 d with aback edge 30 e, corner radii 30 f and a rectangular opening 30 g. Therectangular opening 30 g has an upper blend radius 30 h and a lowerblend radii, and a side wall 30 j. A smaller rectangular section 30 k ispresent to allow for a more bendable or contourable zone that istransitioned into the front round section by radii 30 n and to therectangular section by radii 30 m. Two openings in the plate: 30 p inthe back and 30 q in the front of the rectangular opening 30 g allow forinstrument access.

FIGS. 24 and 25 show the slider 40 generally used with plate assembly200. Slider 40 has a square or rectangular shape with a top surface 40a, a bottom surface 40 b, a front face 40 c, a back face 40 d, a groove40 e on both sides of slider 40, preferably machined with blend radii 40f and 40 g to avoid any stress risers, a central hole 40 h, and achamfer 40 j to break the sharp edge on the hole 40 h where it meets topface 40 a. A slot 40 k cut through the front face 40 c into the centralhole 40 h provides flexibility to the slider 40, and an additional rearslot 40 m provides additional flexibility and a hinge point about whichto flex. A chamfer 40 n and radius 40 p run around the top surface 40 ato break any sharp edges and provide a smooth transition to avoid tissueimpingement. A lower chamfer 40 q transitions the bottom surface 40 band the central opening 40 h, which helps make placement over a spinalimplant easier. As the slider 40 must be compressed into plate opening30 g, chamfers 40 r can be provided to allow for additional clearance inthe slot for the slider 40 to be compressed, as the slider 40 willcompress at an angle as it is inserted into plate 30. An additionalchamfer, 40 s allows the slider 40 to slide into plate opening 30 g.

FIG. 26 shows a plate assembly 200 with the plate 30 assembled with thespherical bearing 3 and slider 40 therein and the plate assembly 200placed over the top of the monoaxial screws 20. Distance between thescrews 20 can be compensated for by slider 40 and angulation of thescrews compensated for by the spherical bearing 3. In FIG. 26, the plateassembly 20 is not engaged with the screw bodies.

FIG. 27 shows the plate assembly 200 with the plate 30 assembled withthe spherical bearing 3 and slider 40 therein and the plate assembly 200placed over the top of the monoaxial screws 20. Distance between thescrews 20 has been compensated for by slider 40 and angulation of thescrews 20 has been compensated for by the spherical bearing 3. In FIG.27, the plate assembly 200 is partially engaged with the top of thescrew bodies 20.

FIG. 28 shows the plate assembly 200 with the plate 30 assembled withthe spherical bearing 3 and slider 40 therein and the plate assembly 200placed over the top of the monoaxial screws 20. Distance between thescrews 20 has been compensated for by slider 40 and angulation of thescrews 20 has been compensated for by the spherical bearing 3. In FIG.28, the plate assembly 200 is fully engaged with the screw bodies 20. Bytightening the set screws 9, the slider 40 and the spherical connectionwill be fully locked, along with the plate 30 to the screws 20.

FIGS. 29 and 30 show a monoaxial screw 5 having a spherical bearingsurface 5 a machined into the surface thereof, such that the bearing andscrew are a one-piece construction. The screw 5, having a top surface 5j, a bone thread 5 b, and a tip 5 c, has a threaded central hole 5 ethat extends to a desired depth and a bottom surface 5 f, which isformed during machining and can be flat, round, drill point, or anothershape. The screw 5 can also be cannulated such that a small hole isprovided through the entire part to allow a k-wire to pass. At least oneslot 5 d in the side of the sphere allows the sphere to be flexible andflex outward when the set screw 9 is tightened. A transition or neck 5 hextending from the bone thread 5 b to the sphere can be provided toprevent the sphere from resting directly on a bone, which would inhibitpolyaxial motion. For purposes hereof, this screw construct is definedas a monospherical screw.

FIG. 31 shows an alternative plate 50 having a top surface 50 a, a frontround edge 50 b, a central hole for containing or accepting a sphericalbearing or monospherical screw, a rectangular section 50 d with a backedge 50 c, corner radii 50 f and a rectangular opening 50 h. Therectangular opening 50 h has an upper blend radius 50 r, a lower blendradii, and a side wall 50 j. A smaller rectangular section 50 k ispresent to allow for a more bendable or contourable zone that istransitioned into the front round section by radii 50 n and to therectangular section by radii 50 m. Two openings in the plate: 50 p inthe back and 50 q in the front of the rectangular opening 50 h allow forinstrument access. This plate configuration allows adjustment of platelength without the use of a separate slider component.

FIG. 32 shows a screw body 8 having a top surface 8 a and two grooves 8b machined into the wall of the screw body 8 opposite each other. Thegroove 8 b has a blend radius 8 d at the top and a blend radius 8 c atthe bottom. Cutting the groove 8 b creates a lip 8 f. A flat 8 e can beadded to provide an easier way to slide plate 50 onto the implant andalso provide a visual alignment clue for the surgeon. Slots 8 j are cutto allow the groove section to have sufficient flexibility such thattightening set screw 9 forces the groove outward against the rectangularside wall 50 j of the plate 50 to lock the screw body to the plate 50.It is noted that the body in FIG. 32 is shown as a polyaxial screw bodyhaving a bone screw with a spherical head 8 g. However, any of thescrews mentioned herein, such as the monoaxial screw, can have thesimple groove configuration.

FIG. 33 shows a dual level construct whereby two plate assemblies areplaced over screws 8, 80 and are subsequently locked by tighteningrespective set screws 9. In this configuration, screw 80 is simply alonger body version of the polyaxial screw body or monoaxial screw. Theextended body of screw 80 has the same features but is longer to acceptthe two stacked plates 50. It is noted that the plates 50 are stacked sothat the taller central screw 80 fits one spherical bearing from oneplate (left) and slides within the second plate (right). Of course, thiscan be inverted, such that the plates 50 join at the identically shapedends.

FIG. 34 shows a dual level construct whereby two plate assemblies areplaced over screws 7, 70 and are subsequently locked by tighteningrespective set screws 9. In this configuration, screw 70 is simply alonger body version of the polyaxial screw body or monoaxial screw. Theextended body of screw 70 has the same features but is longer to acceptthe two stacked plates 1. It is noted that the plates 1 are stacked sothat, in one embodiment, the taller central screw 70 fits one sphericalbearing from one plate and fits within the slider of the second plate orthis configuration can be inverted as shown in FIG. 34 so that theplates 1 join at the identically shaped ends to have the screw 70 fitwithin two stacked sliders, e.g., sliders 2, 40.

FIG. 35 shows a dual level construct whereby one plate assembly withplate 1 is connected to an offset plate assembly having an offset plate60 by placing the plates 1, 60 over screws 7, 70 and subsequentlylocking them by tightening the respective set screws 9. In thisconfiguration, the screw 70 is simply a longer body version of thepolyaxial screw body or monoaxial screw. The extended body of screw 70has the same features but is longer to accept the two stacked plates 1,60. It is noted that the plates 1, 60 are stacked so that the tallercentral screw 70 fits one spherical bearing from one plate (here, plate60) and fits within the slider 2, 40 of the second plate (here, plate1). Of course, this configuration can be inverted so that the plates 1,60 join at the identically shaped ends.

FIGS. 36 and 37 show the offset plate 60. When stacking two plateswithout offset, one plate is higher than the other plate, which raisesthe height of the screw body at the end of the higher plate. This heightdifference can be compensated for by offsetting the plate. The offset iseffectively the thickness of the plate. The offset plate 60 is shownhere as a recessed plate, but it can be any of the versions andvariations discussed herein. The offset plate 60 has a top surface 60 ton the rectangular section 60 j that is offset from the top surface 60 sof the round section of the offset plate 60. This configuration alsocreates an offset of bottom faces 60 d and 60 c. To blend the stepstogether, blend radii 60 m and 60 k, blend the top and back together toavoid any sharp edges. Blend radii 60 f and 60 r run around the plate tosmooth the outside edges. The recessed pocket and other features are thesame as plate 1. Provided is a front round edge 60 a and a central hole60 e for containing or accepting a spherical bearing or monosphericalscrew, a rectangular section 60 j with a back edge 60 b, and arectangular opening 60 u. The rectangular opening 60 u has an upperblend radius 60 r and lower blend radii 60 g, 60 q, and a side wall 60h. Two openings in the plate: 60 n in the back and 60 p in the front ofthe rectangular opening 60 u allow for instrument access.

FIG. 38 is a general illustration 500, showing one instrument variationfor locking the assembly as well as providing features for turning amonoaxial or monospherical screw into bone. Shown is an implantassembly, generally represented by 200, and an instrument 700 thatengages the slots (e.g., 5 d, 7 d, 8 j, 20 r) in the body of the screwhead at the tip 700 c. The shaft 700 a of the instrument 700 connects toa handle 700 b that can be permanently or temporarily attached thereto.A screw driver 600 has a handle 600 a connected to shaft 600 b can turnand lock the set screw (e.g., set screw 9) when instrument 700 acts as acounter torque instrument to prevent rotation of the plate and thescrews.

FIG. 39 details screw engagement features of instrument 700. In anexemplary embodiment, instrument 700 is a tube having a bore. The tip700 c can be recessed to reduce its diameter where it engages the top ofthe bone screw body. To engage the slots, a series of prongs 700 e areprovided, having a first side 700 f and a second side 700 g, such thatflats are formed that can at least partially engage with the side wallsof the slots in the screw heads. Depending on the direction of rotation,not all sides and flats will be in contact. An external chamfer 700 hallows the instrument easier sliding within the bearing, when thatvariation is used. A second chamfer 700 j aids in starting theinstrument 700 within the slots of the screw body. This exemplaryconfiguration works as a bone screw driver as well, and can drive themonoaxial and monospherical screws into a bone.

FIG. 40 shows instrument 700 and prongs 700 e engaged with a screw,which, in this example, is a monospherical screw, but the screw can beany of the variations described herein.

FIG. 41 shows the set screw driver shaft 600 b and tip 600 c engagedwith set screw 9. As previously described, the tip 600 c of the drivercan be of a myriad of different designs, including hex, torx, square,star, or other variations.

FIG. 42 details a variation of an assembly 800 of a plate rod construct92, which is similar to plate 1. However, the middle section 92 m isshown with an alternative round geometry. This configuration creates amore rod-like structure between the first end 92 a, configured to holdthe spherical bearing 96, and the second end 92 j, configured to hold asliding mechanism within a slot 92 k. The spherical bearing 96 isslotted, as in previous descriptions, which allows the bearing to beflexible enough to fit within a pocket in the first end 92 a of theplate rod construct 92. The bearing is then retained within the firstend pocket, but is free to rotate. The nut 98 is then inserted into thebearing 96, which has the ability to retain the nut 98 therewithin. Thiseliminates the need for having a separate nut and saves the surgeon anextra step of placing a nut after the construct 92 is in place over thebone screws 90. A locking nut 98 is turned by features therein with aninstrument. In this case, the instrument engages slots 98 c to turn thenut 98. The locking nut 98 can be shaped in other ways, such ashexagonal, torx, or other forms, to engage the instrument. To preventthe bone screw from turning in the bone, the bone screw is heldrotationally stable by a screw driver shaft engaged with feature 90 a,which, in this example, is shown as a hexagon, but it may be otherforms. The slider second end 92 j has an upper washer 102 and a lowerwasher 101. These washers are assembled to the plate 92 with the lockingnut 98. A retention feature in washer 101 engages a feature on thelocking nut 98, which holds the assembly in slot 92 k of the plate rodconstruct 92. Thus, the locking nut 98 can also be one-piece with theslider, eliminating the need to place a separate nut. When the nut 98engages the top threads on the bone screw 90, the washers 101, 102 arecompressed against the plate rod construct 92, locking the assembly tothe plate rod construct 92. More details of the components in theassembly view of FIG. 42 follow in further figures.

FIGS. 43 and 44 detail the bone screw 90. Bone screw 90 has a thread 90t constructed to engage bone, a first end 90 b, and a second end 90 v.The bone thread 90 t has the option as shown for self-cutting andtapping features 90 m, which allow the screw 90 to tap the bone withouta separate tap. The top of the bone screw 90 has a post with a threadedportion 90 d, a non-threaded portion 90 e, an undercut 90 u, acylindrical section 90 f, and a blend radius 90 p along with a smallchamfer 90 j. The top of the bone screw 90 also has a feature 90 a forconnecting with a screw driver. This is shown in FIG. 44 as a hexagon,but it can be a variety of other forms, including torx, square drive, orothers. The non-threaded portion 90 e allows the nut 98 to engage thepost of the bone screw 90 without having the need to engage the threadsfirst. This makes it much easier to align the threads of the nut 98 tothe threads 90 d on the post. The undercut 90 u is used in manufacturingto eliminate any partial or incomplete threads. This prevents thethreads from cutting too far down the post and allows the locking nut 98the ability to use the entire thread without binding on a partialthread. The cylindrical section 90 f fits within the bottom of thelocking nut to help maintain the concentricity of the locking nut to thepost under loading. Additionally, the cylindrical section 90 f also addsin additional material to reinforce the screw post. While these featuresare beneficial, they could be eliminated and the device could still befunctional. A tapered or chamfered portion 90 g engages variousfeatures, such as part of the spherical bearing 96 and various slidercomponents, the details of which follow in further figures. Between thethread 90 t and the non-threaded portion 90 e of the bone screw 90, isan expanded section including a blend radius 90 r from the thread 90 tto an outer edge 90 k, which has the tapered portion 90 g taperinginwards and upwards from the outer edge 90 k to a blend radius 90 n andthen to a shelf 90 h, which connects to the outer surface of thecylindrical section 90 f. The tapered/chamfered portion 90 g can also beof other shapes, such as partially spherical or elliptical.

FIG. 45 details a variation of the spherical bearing 96. The sphericalbearing has a top face 96 a and a bottom face 96 b. While similar to thespherical bearing shown in previous figures, a set of slots 96 d in thespherical bearing 96 extend from the top face 96 a towards the bottomface 96 b, and a set of slots 96 c extends from the bottom face 96 btowards the top face 96 a. These slots 96 c, 96 d do not cut entirelythrough the spherical bearing 96, but terminate in blend radii 96 e and96 f. These slots 96 c, 96 d make the bearing 96 flexible and capable ofbeing compressed and expanded. A bore 96 k extends through the bearing96. A small top taper or chamfer 96 g extends from the bore 96 k to thetop 96 a, and a small bottom taper or chamfer extends from the bore 96 kto the bottom face 96 b. While it is preferable that the top and bottomtapers or chamfers be of the same angle and size for purposes ofmanufacturing and assembly, they can be of different angles. Also,instead of a taper of chamfer, the faces can be arcuate. As stiffness ofthe bearing 96 is directly related to wall thickness of the bearing 96and the length of the slots 96 c, 96 d, stiffness of the bearing 96 canbe readily adjusted as required. While the surface of the bearing 96 canbe smooth, a surface pattern or roughness 96 j can be machined orapplied thereto. In this example, concentric rings are machined into thesurface. This pattern can also be made by running a helical threadpattern over the spherical surface. Material properties of the sphericalbearing 96 can also have an effect. Softer materials, such as variousgrades of commercially pure titanium can be used, as well as strongermaterials, such as heat treated Ti-6Al-4V. Preferably, Ti-6Al-4V ELIwith a surface pattern is used. This configuration can be replicated inother alloys, such as various stainless steels, and in composite andplastic materials.

FIG. 46 shows part of the general assembly 800 and includes thespherical bearing shown in FIG. 45 held within the spherical bearing endor rod end 92 a. The bearing 96 is elastic enough to be compressed tofit into the end 92 a and expand enough to remain within the pocket inthe end of the plate or rod end 92 a.

FIG. 47 shows that the bearing 96, although held within the plate/rodconstruct 92 can rotate within the pocket in end 92 a.

FIG. 48 shows a cross-section of the plate or rod end 92 a. A recess 92d is cut into end 92 a. This recess 92 d can be spherical, as shown, oran undercut of a different geometry. The spherical recess 92 d orundercut does not need to match the dimensions of the spherical bearing96, and testing has shown that having a spherical recess that is largerin diameter than the spherical bearing diameter provides better testingresults. A chamfer 92 e extends from the top surface 92 b to thespherical opening, which creates an edge 92 g where the chamfer 92 e andspherical surface intersect. A chamfer 92 f extends from the bottomsurface 92 c to the spherical opening, which creates an edge 92 h wherethe chamfer 92 f and spherical surface intersect. These edges help tobite into and grip the spherical bearing 96. By allowing the sphericalseat of the recess 92 d to be larger than the spherical bearingdiameter, the bearing 96 can better engage edges 92 g and 92 h. Asmentioned above, other undercut geometry can also create the proud edgegeometry.

FIG. 49 is a cross-sectional view showing the bearing 96 seating withinthe plate or rod end 92 a. As can been seen, the bearing 96 contactsedges 92 g and 92 h, and not the surface of the spherical recess 92 d.As the bearing 96 is not constrained, it can rotate in all planes. Thediameter of bearing 96 is sufficient to allow the bearing 96 to staywithin the seat that is created by the spherical recess 92 and the edges92 g and 92 h while still allowing the bearing 96 to rotate.

FIG. 50 is a cross-sectional view showing the spherical bearing 96rotated within the plate or rod end 92 a. This view makes it clear thatthe contact points of the bearing are the edges 92 g and 92 h. It is bepossible to leave a small cylindrical portion between the spherical seat92 d and the chamfers 92 g and 92 h or to alter the geometry.

FIG. 51 shows the locking nut 98 having a top surface or face 98 a and abottom surface or face 98 b. A feature, such as grooves 98 c, areprovided in the locking nut 98 so the locking nut 98 can engage and beturned by an instrument. The locking nut can be provided with differentfeatures, such as hexagonal, torx, or other features that can engage aninstrument. A threaded bore 98 d extends from the bottom face 98 btowards top face 98 a. While the threaded bore 98 d can extend throughthe entire locking nut 98, it is also possible to leave a non-threadedportion 98 m. This non-threaded portion 98 m provides additionalmaterial reinforcement to the instrument engagement features 98 c, asthe major diameter of the thread would cut through and reduce thematerial in this area. In certain cases, such as reduction of variousspinal disorders, it is beneficial to have a bone screw 90 with a longerthreaded region 90 d. A fully threaded locking nut 98 allows the lockingnut 98 to engage the threads and still fully seat and lock the assembly.As the screw driver and/or counter torque shaft that engages bone screw90 (and, more specifically, the driving feature 90 a) passes through thecenter of the locking nut 98, a chamfer or blend radius 98 k is providedto help guide the screw driver or shaft into the locking nut 98. Thisvariation of the locking nut 98 has a tapered collar 98 h, which extendsoutward from the external cylindrical wall 98 e. This taper contacts thetaper 96 g within the spherical bearing 96. While the taper 98 g of thecollar 98 h can extend the length of the collar 98 h, it can also betruncated to a cylinder to reduce the exterior diameter while providingclearance for the taper to fully engage in the spherical bearing taper.A lip or small extension 98 f extends from the cylindrical wall 98 e.This lip 98 f can provide a retention ring to hold the locking nut 98inside other components. For example, the spherical bearing 96 can havea groove that allows the lip 98 f to fit therewithin, thereby holdingthe locking nut 98 within the spherical bearing 96 while allowing thelocking nut 98 to turn within the spherical bearing 96. The outside edge98 j of the locking nut 98 is radiused and/or chamfered to prevent softtissue impingement.

FIG. 52 also shows the locking nut, however, this variation removes thetapered collar. A blend radius 98 p minimizes a stress riser where thecylindrical wall 98 e connects to the face 98 r of the larger diametersection 98 s.

FIG. 53 shows a separate tapered collar 99. This collar 99 has an uppersurface 99 a that rests against face 98 r of the locking nut 98 shown inFIG. 52 and a bore 99 c that allows the collar to be slid over lip 98 f.This fit can be just sufficient to allow the collar 99 to slide over thelip 98 f, but still be retained on the locking nut 98. A chamfer orradius 99 d is provided to allow clearance for the blend radius 98 p inthe locking nut 98. This separate collar 99 and locking nut 96configuration is preferable to the all-in-one locking nut 98 shown inFIG. 51 because the collar 99 can rotate independently of the lockingnut 98. When the locking nut 98 is a one-piece construction, assemblytorque creates friction that binds the tapered collar 98 h in thetapered seat 96 g of the spherical bearing. As the torque increases, thelocking nut rotation starts to exert rotational forces on the construct.By having a separate collar 99, the collar 99 rotates independently,thereby reducing the rotational forces to the construct significantly.

FIG. 54 is an exploded view of the assembly 800, which is a preferredversion having the locking nut 98 with the separate collar 99. Forassembly, the bearing 96 is pressed into the plate/rod construct. Asdiscussed previously, the slots allow the bearing 96 to be squeezed downin diameter to fit the smaller opening in the rod/plate construct. Afterassembly, the bearing 96 can rotate within the rod/plate construct. Thelocking nut 98 and collar 99 are assembled and the locking nut 98inserted into the spherical bearing 96, where it is retained. With thebone screw placed in the pedicle, the locking nut 98 is aligned with thenon-threaded post 90 e to find the start of the threads and is turned tosecure the plate/rod construct onto the bone screw 90. To fully lock theassembly 800, torque is applied to the locking nut 98 while preventingthe bone screw 90 from turning by use of a counter torque shaft. As thelocking nut 98 is tightened, the taper features 90 g on the bone screwand 99 f on the collar 99 engage the matching features 96 g and 96 h onthe spherical bearing. This engagement causes the spherical bearing 96to spread outward. As the spherical bearing 96 expands, the surface ofthe bearing 96 engages edges 92 g and 92 h in the plate 92. Additionaltorque generates significant locking of the spherical bearing 98 to theplate/rod construct, thereby locking the angle of the plate/rodconstruct relative to the bearing 96 and the bone screw 90 while lockingthe entire assembly to the bone screw 90. As force is exerted, thebearing 96 may be elastically deforming around the edges 92 g and 92 hso that the spherical bearing 97 is no longer spherical, but partiallyelongated.

Moving away from the spherical bearing, FIGS. 55 and 56 show a variationof the slider. Here, locking nut 98 passes through a top washer 102,through the plate/rod construct (not shown for clarity), and into alower washer 101. The top washer has a top face 102 a and a bottom face102 b. A bore 102 d extends from the top face 102 a through to thebottom face 102 b. To provide a smooth and reduced outside profile ofthe top washer 102, the outside surface 102 c is tapered. Of course, itcan be radiused or have some combination of features, such as radiusedand tapered. A blend radius or chamfer 102 h between the bore 102 d andthe top face 102 a allows for clearance of the blend radius 98 p in thelocking nut 98. A maximum outside diameter of the washer is large enoughto cover at least a portion of the plate/rod connector face. A smallcylindrical section 102 g is provided to eliminate a sharp edge wherethe chamfered surface would intersect the middle face 102 f. A conicalsection 102 e engages the plate/rod construct so that compression of theconical section into the construct creates interference that locks theslider in position. The lower washer 101 has a top face 101 a and abottom face 101 b. A cylindrical surface 101 c has flats 101 d machinedinto the surface. These flats 101 d align and slide within the slot ofthe plate and prevent rotation of the lower washer 101 relative to theplate/rod construct. The lower washer section 101 c can also be squareor rectangular. A radius or chamfer 101 j between face 101 d and wherethe face would intersect face 101 e is preferred to help provide afeature that the plate/rod construct can bite into, which, in practice,provides better gripping strength to the construct. This radius/chamferfeature 101 j can be removed and the locking can still be sufficientunder high enough torque. Surface 101 e is a flat surface for engaging abottom of the rod/plate construct. As with the top washer 102, a chamfer101 g or radius helps to reduce the profile and bulk of the lower washer101. To avoid a sharp edge, a radius 101 k and a small cylindricalsection 101 f are provided. Inside the lower washer 101, a lip 101 nextends inward from bore 101 h, and a chamfer 101 p extends from the lip101 n to the top surface 101 a. This lip 101 n and chamfer 101 p allowlocking nut feature 98 f to be pressed into the lower washer 101. Oncethe feature 98 f is passed the lip 101 n, the individual componentsbecome securely fastened together while still allowing the locking nut98 to turn freely, as the locking nut lip 98 f is within the larger bore101 h. This plate/rod construct provides a self-contained singlefunctional unit that does not require any assembly or the addition of alocking nut at the time of surgery.

The components in FIGS. 55 and 56 are shown in FIG. 57 with theplate/rod construct 92. The lower washer 101 slides within pocket 92 ksuch that the flat surfaces 101 d are aligned parallel to the long axisof the pocket. Smaller openings 92 m and 92 n extend through to pocket92 k. This allows the slide assembly to slide within pocket 92 k but,even at the end of travel within the pocket, openings 92 m and 92 mstill remain accessible. This accessibility allows an instrument to beinserted to act as a lever and move the sliding assembly in a desireddirection. This ease of movement allows very effective compression ordistraction of the spinal elements, by lengthening or shortening thedistance between the center of the sliding assembly and the center ofthe spherical bearing.

FIGS. 58 and 59 show an alternative slider 900 that also allows rotationof the bone screw 90. Using the same bone screw as the spherical bearingend reduces inventory and simplifies a surgical procedure. Inparticular, by providing a spherical seat in a lower sliding component107, the bone screw taper or arcuate surface 90 g can rotate within theseat. This rotation is in a single plane. The upper sliding component106 has an arcuate surface 106 a, here shown with a grooved or toothpattern 106 t. The arc surface 106 a is on approximately the same centerof rotation as the spherical seat in lower sliding component 107. Whenthe locking nut 98 is tightened, the nut 98 forces upper and lowersliding components 106, 107 against the plate/rod construct 92, whileforcing washer 105 against upper sliding component 106, therebysimultaneously locking the assembly to the plate and the angulation ofthe bone screw 90. FIG. 59 shows the exploded view of the assembly andthe order in which the components are assembled. The details of thecomponents are shown in FIGS. 60 through 64.

The lower sliding component 107 shown in FIGS. 60 and 61 includes arectangular block having a upper surface 107 a, a lower surface 107 b,and side walls 107 c, which are of sufficient dimensions to fit withinthe slot 92 k in the plate 92 and allow sliding therein. Surface 107 gis configured to contact the bottom of the plate/rod construct 92 with abend radius 107 h that reduces stress risers while providing materialfor the bottom edge of plate slot 92 k to engage for better locking ofthe assembly to the plate. Of course, it is possible to configure thelower sliding component 107 so that the plate 92 contacts the radius 107h and not surface 107 g and still achieve assembly locking. The feature107 h can also be a small chamfer and not a radius. The internal bore107 j is an oblong or oval pocket and the lip 107 k that extends inwardsis also oval or oblong. This oval or oblong shape gives the locking nut98 clearance to pivot and allows angulation of the bone screw 90. Thelip 107 k is present to retain the locking nut 98 in the assembly byallowing the lip 98 f on the locking nut 98 to be pressed past it untilthe lip 98 f is in the larger oval or oblong shaped bore 107 j. Thisretains the locking nut 98 but still allows the nut 98 freedom to turn,slide, and move up and down within the internal bore 107 j. A chamfer107 m helps the locking nut lip 98 f enter the bore 107 j. A sphericalseat 107 r allows the bone screw's tapered or arcuate surface 90 g tosit therewithin and rotate. Where the oblong or oval bore and thespherical seat 107 r intersect, a small shelve 107 p is created. Toreduce bulk of the lower sliding component, blend radii and chamfers 107f are machined into the component 107. The lower sliding component 107can also have a feature to engage the top sliding component 106. Thiscan be, for example, a groove or slot in the side wall 107 c thatmatches an extension from the top sliding component 106. This can be asingle tab in a slot or multiple tabs into multiple slots as well or avariety of other engagement approaches, such as a groove or slot in thetop sliding component 106 and a tab extending from the lower slidingcomponent 107.

As shown in FIGS. 62 and 63, the top sliding component 106 includes atop arcuate surface 106 a and a bottom surface 106 b. The top surface106 a can be roughened or textured, such as is shown. In this example,small grooves are machined into surface 106 a. This is one example;there are different ways to apply a textured surface, includingcrosshatching, blasting, chemical etching, and/or wire EDM cutting ofsplines or features, among other approaches. This surface can also besmooth without texture; however, better grip is provided with the matingcomponent when a texture is present. A front wall 106 c and a back wall106 d, along with the longer side walls 106 e, 106 f form a rectangularshape that can fit within the plate/rod construct opening 92 k and havesufficient clearance to slide Like other components describedpreviously, the geometry of the part can be different, such as square orround, with features cut into the shape to work in the manner describedherein. The sides 106 e, 106 f are cut into the rectangular shape sothat the top surface 106 a extends beyond and is wider than therectangular section that fits within the plate opening 92 k. Tapers orchamfers 106 h allow for the sides of the rectangular section that fitswithin the plate/rod construct to contact the sides of the opening 92 k,to provide a press fit with the plate when the top sliding component isfully seated in the slot. The tapers or chamfers can be eliminated;however, they provide additional strength to the construct and furtherresistance to sliding when the assembly is locked. An oblong orelliptical bore 106 g allows the locking nut 98 to pass through the topsliding component 106. To reduce the amount of material removed from thetop sliding component 106 by the bore 106 g, the bore 106 g is machinedat a taper angle, such that faces 106 j and 106 k are angled or conicalin shape.

The top washer 105, as shown in FIG. 64, has a top surface 105 a and abottom surface 105 b. The generally cylindrical outer wall 105 h ischamfered towards the top surface 105 a to provide a smooth surface withless bulk for reducing tissue impingement. Of course, this surface canbe partially spherical or arcuate or a combination thereof. It ispreferable to cut an arced surface 105 c into the bottom surface 105 bin the washer 105 to create edges 105 j and 105 k, which help to engagethe surface roughness feature 106 t on the top sliding component 106.The arc in this case does not need to match the same dimension as thetop surface 106 a and can be smaller. Of course, the arcs can matchexactly and the surface roughness or teeth can also be added to arc 105c or to some part of the bottom of the washer 105 to also engage thesurface of the top sliding component 106. The top washer 105 also has athrough-bore 105 d and, preferably, a counter bore 105 e, which allowsthe head of the locking nut 98 to sit within to reduce overall heightand profile of the locked assembly.

As shown in FIG. 65, in which the locking nut 98 is tightened, thelocking nut 98 engages the thread on the bone screw 90, which compressesthe top sliding component 106 and the bottom sliding component 107against the plate rod construct 92 while simultaneously locking theangle and location of the slider. Partial locking can also beaccomplished by tightening the locking nut 98 to less than a full torquevalue, which can allow the slider to still slide while resisting changesin screw angle.

FIG. 66 shows in the assembly in a sectional view to detail how thevarious components fit together. As shown, the locking nut lip 98 f fitswithin the lower sliding component 107 and is retained by lip 107 k. Thesurface 90 g of the bone screw 90 rests in the spherical seat 107 e ofthe lower sliding component 107. When tightened, which is done by usinga counter torque driver engaged with the driving feature of the bonescrew 90 a and by turning the locking nut 98 clockwise, all thecomponents are drawn together and locked together.

FIG. 67 highlights the bone screw engaging feature 90 g can be partiallyspherical or arcuate, and is shown with reference numeral 90 g′. Thishas been discussed earlier but, for clarity, is shown herein.

FIG. 68 is the same as FIG. 66, but has the bone screw shown in FIG. 67with the arcuate or partially spherical surface 90 g′ replacing thetaper 90 g.

As discussed above, it can be beneficial for the top sliding component106 to engage with the lower sliding component 107. Duringflexion-extension loading, whereby force is placed on the screw, theload tends to force the sliding components apart in opposite directions.If the washer 105 is fully engaged with the teeth 106 t on the topsliding component 106, the lower sliding component 107 may slide morethan the top sliding component 106. To prevent this from occurring, ananti-sliding feature or features in the two components is beneficial.These can be tabs in slots or grooves, or other ways, such as a pin orpins in holes. In addition, the top sliding component 106 and the lowersliding component 107 can be secured together in the plate rod constructso that tabs engaged in slots lock the two components 106, 107 together,such as in a snap together fit. The two components can also be looselypress fit together, although any approach to locking the upper slidingcomponent 106 and lower sliding component 107 must allow the componentsthe ability to move towards each other so that compression against theplate rod construct can occur to lock the assembly and the slidingcomponents to the plate rod construct. Details of one variation of thisare shown in FIG. 68A.

FIG. 68A shows that the top sliding component 106 has a slot 106 p cutinto the side wall 106 e. This slot 106 p extends through the side ofthe part. The shape is cut leaving prongs, hooks, or small extensions106 r that extend inward. This creates small features that can engagethe lower sliding component 107. Small slots 106 s can be provided tomake the small hooks flexible, to allow for easier engagement with thelower sliding component 107. The lower sliding component 107 has part ofthe side wall 107 c cut away, leaving two tabs or arms that extendupwards. A recess 107 u is cut into the wall, which leaves an overhang107 t left behind. Thus, the prongs or hooks 106 r can slide over theoverhang 107 t and snap into the recess 107 u. This effectively holdsthe two components together. The overhang 107 t in the lower slidingcomponent 107 is shaped to contact wall 106 v in the top slidingcomponent 106 so that there is minimal clearance between wall 106 v andoverhang 107 t. This configuration allows for sufficient room for thehooks or prongs to slide up and down within the recess 107 u, whichallows top sliding component 106 to slide up and down relative to bottomsliding component 107 and, when in a final locking state, overhang 107 tengages wall 106 v. This minimizes any possible sliding of the twocomponents after locking the assembly. This makes the assembly morerigid and increases flexion-extension test values.

FIG. 69 is an alternative slider 950 that also allows angulation. Thebasis of this variation is a cube 108 configured to flex outward whenthe locking nut 98 and collar 99 engage the top internal tapered surface108 d of cube 108 and the screw surface 90 g engages the bottom taper108 e within the cube 108. As seen in FIG. 70, the cube 108 is cut witha series of small slots 108 f, 108 g, 108 h. These slots, such as 108 g,can extend from the top face 108 a or from the bottom face 108 b, suchas slot 108 h. These slots reduce the rigidity of the cube 108 and allowit to expand outward as the locking nut 98 is tightened on the post ofthe bone screw 90. Shorter length slots, such as 108 f, direct the forcepartially above and below a lip 109 b and chamfer 109 c in plate 109.Small cylinders 108 m, 108 n are machined into the cube 108 to formpivot points. These cylinders 108 m, 108 n also help to retain the cube108 in the plate/rod construct while allowing rotation of the cube 108.These cylinders 108 m, 108 n fit within an undercut 109 d in plate 109.As the cube 108 is flexible, it can be pushed down into the plate/rodconstruct and, when properly seated, the cylinders 108 m, 108 n willexpand outward to fit within the undercut 109 d. During locking,surfaces 108 j and 108 k at least partially engage the internal surfaceof the plate/rod construct 109.

FIG. 71 is a cross-sectional view of the cube 108 that better shows thetapered features 108 d, 108 e connected to the bore 108 c. The amount offlexibility of the cube 108 is directly affected by the length, number,and placement of the various slots. Thus, the slots can be tailored tothe application. The cube 108, does not need to be a cube; it can beother shapes, such as rectangular, modified cylinder with flats, oranother shape as desired. The engagement of the tapered surfaces 108 d,108 e of the cube 108 and the surface 90 g of the bone screw as well asthe collar 99 and the locking nut 98 can cause significant outwardlydirected force to lock the location and angle of the cube 108.

FIG. 72 shows the assembly of FIGS. 69 to 71 prior to placement on thebone screw. As in previous embodiments, the locking nut 98 can beincorporated into the cube 108 making easier for the surgeon to use.Either the locking nut 98 can be slightly press fit into the cube 108,or retained in the cube 108 by engagement of the lip 98 f of the lockingnut 98 in a groove cut inside the bore 108 c of the cube 108. Thedetailed sectional view of the locked assembly 950 is shown in FIG. 73.

FIG. 74 shows an exploded view of an alternative slider 1000. Thisslider 1000 allows for screw angulation and sliding and includes a topwasher or collar 111, a upper sliding seat 112, a plate/rod construct110, a lower bearing 113, and a lower sliding seat 112′. This variationcan function with bone screw 90 having the taper 90 g or arcuate surface90 g′.

Detailing the components shown in FIG. 74, FIG. 75 shows the collar 111having an upper surface 111 a, a lower surface 111 b, and a central bore111 c. Surface 111 d is spherical or partially spherical. A smallcylindrical portion 111 e is below the surface 111 d (e.g., sphericalportion). The face 111 f is radiused or tapered to reduce soft tissueimpingement and the intersection between 111 f and surface 111 d isradiused 111 g to avoid any sharp edges. In FIGS. 74 and 76, the uppersliding seat 112 and the lower sliding seat 112′ (which is similar inshape to upper sliding seat 112 but turned over) include an uppersurface 112 a and a lower surface 112 b. A spherical seat 112 c ismachined in the top face and a through-bore 112 d extends through thepart. Two arms 112 e are conical in shape and engage the chamferedsurfaces 110 d and 110 d′ of the plate or rod construct. FIG. 77 detailsthe plate or rod construct 110, which has an upper surface 110 a and alower surface 110 b. A slot 110 c extends through the construct 110. Astep cut into the top and bottom surfaces 110 f creates a ledge 110 g. Achamfer 110 e is configured to engage the arms 112 e on the uppersliding seat 112. Two small pockets 110 h are smaller than slot 110 c.The lower bearing 113, as shown in FIG. 78, has an upper surface 113 a,a lower surface 113 b, a spherical or partially spherical seat 113 c, acylindrical wall 113 d, and a blend radius 113 h to avoid any sharpedges. A bore 113 e extends through the lower bearing 113 and a lip 113f extends inward into the bore 113 e to create a ledge 113 g. A chamfer113 j runs from top edge 113 b to the lip 113 f to provide a smoothtransition and guide surface. During assembly, the locking nut 98 ispressed through the upper bearing 111, the upper sliding seat 112, theslot 110 c in the plate/rod construct, and the lower sliding seat 113.The locking nut 98 is then pressed into the lower bearing 113 so thatthe lip 98 f on the locking nut 98 engages and slides under the lip 113f. This locks the assembly together while allowing it to be loose enoughto slide and move in the slot 110 c. The bone screw 90 seats in thebottom of the lower bearing 113 in a tapered seat machined in the bottomof surface 113 a and is configured to lock to the tapered surface 90 gon the bone screw 90.

In use, the assembly and components generally shown as 1000 and in FIGS.72 through 78 work such that the upper sliding seat 112 and the lowersliding seat 112′ can slide independently relative to each other. Thisallows angulation and sliding of the assembly and is shown in FIG. 77.As the upper sliding seat 112 and the lower sliding seat 112′ move, thespherical seats 111 d and 113 c can move within the matching sphericalseats in the upper and lower sliding seats 112 c, 112′c. It is notedthat, as the upper and lower seats 112, 112′ slide, the distance fromcenter to center of the spherical seats 112 c, 112′c increase. Thelocking nut 98 has sufficient threads to compensate for this nominaldifference. When the assembly is locked, the conical feature 112 e andboth 112 and 112′ lock into the tapered features 110 d and 110 d′,respectively, thereby locking the sliding and angulation of theassembly.

Another variation of the assembly, as generally shown as 1200 and inFIG. 80, uses a flexible cube 115, slotted pins 114 that fit over theedges of the plate, and a locking approach whereby tightening lockingnut 98 on the threads 90 d of bone screw 90 cause the flexible cube 115to compress against the pins 114, which compress against the top andbottom surfaces of the plate/rod construct 92 and lock the angle andlocation of the flexible cube 115 and assembly 1200. As shown in FIGS.80 through 82, the flexible cube 115 has a top surface 115 a, a bottomsurface 115 b, a front surface 115 h, a back surface 115 j, a first side115 g, and a second side 115 k. A bore 115 e extends through theflexible cube 115 from the top surface 115 a to the bottom surface 115b, and a chamfer 115 f extends from the bottom face 115 b to the bore115 e and is configured to match the taper feature 90 g on the bonescrew 90. A side hole 115 c extends through the cube 115 from first side115 g to second side 115 k. This side hole 115 c allows the pins 114 tofit and turn therewithin. A slot 115 d allows the cube 115 to beflexible so that force on the top surface 115 a and the bottom surface115 b causes the cube 115 to squeeze inward, thus reducing the diameterof opening 115 c and apply pressure against the pins 114. The pins 114have a front surface 114 a, a back surface 114 b, a slot 114 c of awidth to fit a width of plate 92 and a small slot 114 d, which creates asmall area of material/metal 114 e that acts as a hinge to allow thepins 114 flexibility and to be compressed by the cube 115. As shown inFIG. 82, when the locking nut 98 is tightened on the threads 90 d of thebone screw 90, the locking nut 98 and screw feature 90 g compress thecube 115 against the pins 114, which causes pins 114 to compress againstthe plate 92, thereby locking the angulation and sliding of theassembly.

FIG. 83 shows a variation of a polyaxial screw assembly 1300, which issimilar to previous polyaxial assemblies. However, the key component 122is effectively a collet with external threads. The locking nut 98extends through a top washer 120 and plate 92 and engages sleeve 121.The collet 122 snaps over the head 6 c of the bone screw 6. When thecollet 122 is drawn up into the sleeve 121, the collet 122 is compressedagainst the screw head 6 c while the washer 120 and sleeve 121 aresimultaneously compressed against the plate/rod construct 92, therebylocking sliding and angulation. It is also possible to partially lockangulation and still have sliding capability until the locking nut 98 isturned further. The top washer 120, also shown in FIG. 86, is simply awasher with a top surface 120 a and a bottom surface 120 b configured tocontact the surface of the plate/rod construct 92. An internal bore 120c allows the locking nut 98 to pass through.

FIG. 84 details the collet 122 of the polyaxial screw assembly 1300. Thecollet 122 has a top surface 122 a, a bottom surface 122 b, a drivingfeature 122 c for engaging a driver instrument, and a bore 122 dextending through the collet 122. A spherical seat 122 k engages thehead 6 c of the bone screw 6. The head 6 c of the bone screw 6 can belarger than the diameter of spherical seat 122 k so that the screw head6 c causes interference with the spherical seat 122 k and spreads thecollet 122 outward. The slots 122 m allow the collet 122 the flexibilityto spread. These slots 122 m can vary in height in number, as needed. Athreaded portion 122 e engages the threads 98 d in the locking nut 98and an undercut feature 122 f eliminates any incomplete threads andallows locking nut 98 to fully seat and use the entire thread length, ifnecessary. The external collet section shown as 122 h is configured toengage sleeve 121. While shown here as cylindrical, it can be tapered.Also, if the head 6 c of the bone screw 6 is larger than the diameter ofthe spherical seat 122 k, it will cause the collet 122 to flex outward,created a tapered shape. A small cylindrical section 122 j allows thecollet 122 to be partially drawn into sleeve 121 without causing atightening of the assembly. Two chamfers 122 p, 122 r allow the collet122 to slide within the sleeve 121 without catching on sharp edges. Ofcourse, there are multiple variations possible, such as extendingsection 122 h and eliminating the step 122 j, or tapering the surfacesuch that no step is necessary. The sleeve 121 can also have an internaltaper to match or interfere with the tapered surface.

FIG. 85 shows sleeve 121 with an upper surface 121 a and a lower surface121 b. A cylindrical bore 121 c extends through the sleeve 121. It canalso be tapered or partially cylindrical and partially tapered. Acounter-bore 121 d allows clearance for the bottom of the locking nut98. A conical surface 121 e engages with the plate rod construct 92 sothat, as the assembly is tightened, the conical surface 121 e engagesthe edge and/or chamfer on the plate rod construct 92 to assist inlocking the sleeve 121 to the plate 92. If the edge is sharp or minimalradius, the edge will deform the conical face, which creates a bindingand locking feature. The outer lip 121 f of the sleeve creates a flatsurface for engaging the bottom face of the plate rod construct 92 orprevents the sleeve 121 from travelling any further than necessary. Ifthe conical feature 121 e fully engages, the outer lip 121 f may notengage part or all of the bottom of the plate 92. A chamfer 121 g allowsfor easier assembly and sliding of the sleeve 121 on the collet 122.

FIG. 86 further shows assembly 1300 in a cross-sectional view toillustrate how the components engage when they are fully locked. Byturning the locking nut 98, the collet 122 is drawn upwards into thesleeve 121. This movement compresses the collet 122 against the screwhead 6 c of the screw 6 and draws the sleeve 121 and the washer 120against the plate rod construct 92. This action locks the angulation andlocation of the assembly within the construct 92. While angulation andsliding can be locked simultaneously, angulation can be locked orpartially locked first by not completely tightening the locking nut 98,and then locked to the plate by further tightening. This is potentiallybeneficial in compression and distraction of the spine. FIGS. 87 and 88show a connector 140 for expanding a single level construct into amulti-level construct. This connector 140 has a partially threaded postsimilar to a screw post and an opening to accept an extended screw post.This effectively adds an additional partially threaded post to a screw,thereby creating two threaded posts to attach rod/plate connectors. Theconnector 140 has a connector top surface 140 a, a bottom surface 140 b,a first rounded face 140 c and a second face 140 d. A partially threadedpost 140 e has a top surface 140 f, a non-threaded region 140 g, athreaded section 140 h, and a recess 140 j cut into a post 140 k so thatthe recess 140 j allows the threads to be good threads even at thebottom of the threads. The post 140 e is machined or formed on top of atapered section 140 m and, as the post 140 e is smaller than the topdiameter of taper 140 m, creates a shelf 140 n. A chamfer 140 p breaksthe edge between the taper 140 m and shelf 140 n, which allowscomponents seating on the taper 140 m to find and engage the taper 140 mwithout contacting a sharp edge. The connector 140 can be recessedrelative to the start of taper 140 m, which creates a small cylindricalfeature 140 r. This feature 140 r can also be taller to create a talleroverall post without affecting the critical dimensions of the remainingfeatures above the cylindrical feature 140 r. On the other end of theconnector is a tapered feature 140 s, which can be identical to 140 m indimensions. This is also on a small cylindrical section 140 w, theheight of which can be increased or reduced. The intersection of topsurface 140 t and taper 140 s is chamfered 140 v to avoid a sharp edgeand allow interfacing components to find and seat on the taper 140 swithout engaging a sharp edge. A bore 140 u passes through the connector140 and is generally centered within the taper 140 s. The bottom opening140 x of bore 140 u, as seen in FIG. 88, matches the screw post base,which is preferably tapered. Thus, when the taper of a screw postcontacts the preferred taper of 140 x, the two rigidly engage. Ofcourse, it is not necessary to have this feature be a taper, but just acylindrical bore that contacts the base of the screw to make sure theconnector can be secured in the right position relative to the height ofthe partially threaded post on the screw.

FIG. 89 clarifies the partial assembly of the connector 140 by showing amodified bone screw 142. As shown in FIG. 89, the post of the bone screw142 has a partially threaded post section 142 d and a non-threadedsection 142 e that is identical to the previously shown bone screws 90.The main difference in this bone screw 142 is that an extended section142 f is provided such that, when inserted in connector 140 and theassembly is locked, the height of the threads is correct to insureproper component assembly and locking. As per the other bone screws, arecess 142 j is provided to allow a locking nut to be able to use thefull length of the threads. The taper or chamfer 142 g is the same as inthe previous bone screws 90. The partial section 142 t represents anarea of bone screw threads, which are not illustrated.

FIG. 90 shows the connector 140 with the addition of splines 140 v andmatching splines 144 f on a bone screw 144. These splines 140 f, 144 f,once engaged, can assist in providing anti-rotational capability to theconstruct. Bone screw 144 has the same general features of bone screw142, included the threaded portion 144 d, the non-threaded portion 144e, and the tapered section 144 g.

FIG. 91 shows a full two level assembly 2000 when connector 140 is used.As an alternative to this exemplary embodiment is an embodiment thatdirectly connects the two plate constructs 92 to one another without theconnector 140. To make such a connection, the non-threaded 142 e andthreaded 142 d post sections of the bone screw 142 is/are lengthened sothat two of the spherical bearings 96 can be stacked one on top of theother with the lengthened sections in the center of both bearings 96. Insuch a configuration, all that is needed is to place the extended postsections 142 d, 142 e through two plate constructs 92 having therecesses 92 d of the spherical bearing sections one on top of the other,slide the two bearings 96 on the post sections 142 d, 142 e and into thetwo recesses 92 d, to insert a single locking nut that is approximatelytwice as long as those locking nuts 98 through both bearings 96, and tothread the interior threads of the extended locking nut onto thethreaded post section 142 d. As can be seen, the connector 140 acts as abridge providing an additional partially threaded post to attach anotherplate rod connector. In this example, the spherical bearing ends arefacing each other. The connector 140 allows the spherical bearings 96enough room for the bearings 96 to rotate until they are locked. Ofcourse, the opposite slider ends can also attach to the connector 140.However, the sliders should be as far as possible to the end of theplate rod connectors to allow both plate rod connectors to fit. It isnoted that, in this example, the bone screws 90 have a cylindricalextension 90 x that raises the construct slightly off the bone foreasier placement under certain anatomical conditions.

FIG. 92 shows an instrument 160 for compression and distraction. Thisinstrument 160 has a handle 160 a, a shaft 160 b, and a tip 160 c. Thistip 160 c, shaped like a cam or screw driver blade has a leading edge160 e, which can be tapered or radiused for easier placement in a platerod construct pocket, such as 30 p, 60 p, 92 n, 92 m, etc., and a face160 f. The face 160 f can be flat, round, oval, cam shaped, or anothershape. As the tip 160 c is generally rectangular, the tip 160 c createsa cam in function. When the handle 160 a is turned, the tip 160 cengages the slider and an edge of the pocket so that, the further thehandle 160 a is turned, the further the slider is displaced.

In surgical use, the most common application of the embodimentsdescribed and shown herein is in the treatment of the lumbar spine.Spinal screw assemblies or hooks having a saddle or opening for a rodare screwed into the pedicles or attached to a bone structure of thespine. This provides excellent visualization of the screw placement siteand anatomy. Depending on the variation, either a bone screw with aspherical head or a threaded post is placed, or a combination of either.While the variations shown depict either one or the other, one skilledcan see how the various features can be combined when multiple levelplates with three or more screws are used.

When spherical head bone screws are used, polyaxial assemblies aresnapped over the bone screw heads. Of course, the modular nature of theconfiguration allows the polyaxial screw assembly to be attached to thebone screw head first, and the entire assembly implanted as one piece.In a single level case whereby only two vertebrae are to be fused, asingle plate is used, preferably on each side of the spine and rightsize selected. Either a measurement of the distance between the screwscan be taken or a template used to determine the proper plate size. Theslider and its variations allow for a single plate to cover a range ofscrew head distances, which significantly reduces inventory. Once thecorrect size plate is selected, the spherical end of the plate withbearing is snapped over the top of one of the screw heads, and the plateis adjusted and angled until the slider end of the plate captures thesecond screw head. The set screws are then tightened to lock theassembly.

When the slider variation is used, such as in assemblies generally shownin 100 and 200, tightening the set screw in the slider screw causes thescrew head to expand, thereby spreading the slider outward to exertforce against the inside of the plate and locking it in position. Theinside of the plate and/or outside of the slider can also have teeth ora surface finish to provide the surgeon a way of temporarily holding theslider in the desired position.

The spherical interface is also locked by spreading of the screw bodiescaused by tightening the set screw.

It may also possible to place the plate first and the screws through theplate. However, this is more difficult than having bone anchorspre-installed.

When Monoaxial screws are used, the same surgical procedure applies.Place the screws, measure the distance between the screws, select thecorrect plate, place the plate over the screws and lock the assembly. Inthe case of the monospherical screw, this screw eliminates the need fora spherical bearing in the end of the plate. However, the slider holealso becomes spherical to accept the spherical screw head. This allowsmore angulation and adjustment.

In a multilevel construct, one plate is stacked over the top of anotherplate. The advantage to this is that contouring of long plates isminimized or eliminated. In multilevel constructs, the pedicles are atcompound angles and vary in medial-lateral offset. Thus, connecting aseries of screws by a single long plate is challenging and oftenrequires compromising the ideal position of the screws in the pedicles.By connecting two screws at a time, offset does not apply, as each plateconnects only two screws.

The spherical bearing or monospherical screw compensates for angulationin all planes. Without such a connection to the plate, the plate wouldremain perpendicular to both screws, making it almost impossible toplace. Of course, while the bearing is shown held within the plateassembly, it can also be pre-assembled on the screw body.

While discussed previously, the plate can be a plate but also a rod withfeatures on the ends that match the features shown in the variousfigures and described accordingly. This approach allows the sectionbetween the ends to be round, which can have a few advantages. First,the stiffness to the construct can be matched to that of a 5.5 mm rodsystem, or any other desired stiffness. Also, components designed forround rods, such as off the shelf rod to rod connectors or crosslinkscan directly attached to the round section, as can be other polyaxialscrew systems, for the treatment of multiple levels. Side connectors canalso be used to attach to the round section to treat multiple levelfusions and fix to the spine. In addition, the round section can bereadily contoured to better match the curvature of the spine while allowthe surgeon the ability to do in-vivo bending, when necessary.

By providing the spherical bearing with slots, the bearing, such as thatshown in FIG. 45, the bearing can be readily assembled in the plate, asit is flexible to be inserted within an opening in the plate/rodconstruct. With slots that extend from the top and bottom of thespherical bearing, the locking of the spherical bearing to the plateoccurs by spreading the bearing outward by contact of the taperedsurfaces on the screw and locking nut collar with the features insidethe spherical bearing. This outward expansion is extremely efficient inengaging the seat in the plate rod construct and locking the sphere tothe construct. Surface finish and material do affect the strength of thelocking when tested. Ti-6Al-4V ELI with a machined tooth pattern workswell, as does smooth Commercially Pure (CP) Titanium. Ti-6Al-4V ELI isharder and stronger than CP Titanium and does not work as well withoutsurface roughness, as the surface is unable to effectively grip theedges of the plate/rod spherical seat. CP Titanium with surfaceroughness does not work as well either, as the material is too soft tohold the surface roughness without shearing the rough surface. Ofcourse, there are different grades of titanium, and different alloys,each may have a different affect and require different surface or nosurface treatment. The alloys chosen are based on their standard use inthe industry, biocompatibility, and properties.

Surface roughness on the spherical bearing can be applied in a number ofways, including machining, chemical etching, grit blasting, or othermeasures. It is preferable to provide a machined feature that createssmall grooves around the surface. While this can be done as individualcircular grooves, the machined pattern can be run in a helix,effectively creating a shallow thread over the spherical surface. It ispreferable to create the surface over the entire spherical area to becertain that rotation of the sphere in the plate still maintainsengagement of the surface roughness pattern with the edge of thespherical pocket in the plate regardless of the angulation of thespherical bearing when on the screw post.

While the plate is shown as having two separate openings, it isunderstood that the plate could have one opening with a slot in themiddle of the plate connecting the openings, or multiple openings toaccept an intermediate screw or instrument.

When the screw used is that shown as bone screw 90 with a threaded post90 d, the screw is placed first, as in the previous versions. As theassembly is placed over the screw posts, it is desirable to prevent thescrew from rotating during locking and applying torque to the spine.Thus, the counter-torque tool engages the feature 90 a, which may be atorx, hex, square drive, or other shape and allows the surgeon toprevent the screw from turning by preventing the counter-torque toolform turning while torque is being applied to the locking nut. In thepreferred embodiment, the collar 99 free floats on the locking nut 98,which is highly beneficial because the collar minimizes unwanted torquebeing transferred to the sphere during tightening, which also minimizestorque to the plate/rod construct as the sphere engages the sphericalseat. The counter torque tool can be cannulated to go over a k-wire fora minimally invasive approach. The nut driver can be placed over thecounter-torque shaft and lowered until it engages the features in thelocking nut 98. Torque is applied until the assembly torque is reachedand the tools removed. This leaves a very low profile system.

For multilevel constructs, a simple connector 140 can be used to connectmultiple plates. This configuration allows a single component along withan extended screw-post bone screw to handle more complex procedures witha minimum of added components. For example, in a two-level case, normalbone screws 90 are placed at either end of the construct and an extendedpost bone screw, such as shown as screws 142, 144, is placed in themiddle pedicle. Connector 140 is then placed over the extended bonescrew post. A distance between the screw heads is measured and thecorrect rod plate connectors are selected and secured to the threads onthe screw heads by way of the locking nuts 98.

As the slider end allows for compression and distraction of the spine,as discussed previously, the surgeon can measure with a gauge and findthe size desired based on whether compression or distraction is needed.As the slider has a set amount of travel, for example, 5 mm, it ishelpful to know where the slider will be when the assembly is firstattached to the bone screw posts. For example, if the pedicles are 25 mmapart and the surgeon wants to decompress and expand the distance to 30mm, the plate/rod construct should be sized so that the sphericalbearing opening and the slider opening are at 25 mm but where the slideris at the end of the travel towards the spherical end. Thisconfiguration allows for placement and a full 5 mm of decompression. Ofcourse, if this is reversed so that the pedicles are 25 mm apart but thesurgeon wants to compress the spine to 20 mm, the initial position ofthe slide should be at the far end away from the spherical bearing, thusallowing full travel length back towards the spherical bearing. In thecase of a need to do temporary compression or distraction, the implantscan be tightened, the necessary procedure done, the implants loosenedand adjusted to the proper distance, and the assembly re-tightened. Itis also possible to simply provide temporary friction or pre-lock ofcomponents by not applying the full locking torque to either end of theassembly.

As the spine flexes in multiple planes, stabilization of the spine ononly one side of the spinous process is insufficient. Therefore, in anormal spinal procedure, stabilization of the spine requires implantsand fixation on both sides of the spinous process. For example, in asingle level fusion of L4-L5 of the lumbar spine, bone screws areinserted into both pedicles on L4 and both pedicles of L5. The screwsare then connected by one of the plate-rod constructs described hereinon each side of the spinous process, i.e., the screws on the left of thespinous process are connected and the screws on the right side of thespinous process are connected. This creates two multi-plate constructsthat run in the cephalad-caudad direction to provide support to thespine during the fusion process. By using the connector, as shown inFIGS. 87 to 91, a longer screw post 144 or screw section 142 f, or anextended screw body as shown in FIGS. 33 and 34, allows two plateconstruct 92 ends to be stacked on top of each other. In this way, it ispossible to create plate constructs 92 that extend over a multiplepedicle or multiple vertebral length. By combining plate constructs asindicated, there is no limitation on the length of the construct chainor the number of levels that can be treated. Different length plateconstructs can be combined to compensate for variations in distancebetween bone screws placed in the pedicles.

As the assembly is self-contained and small, it is possible to supplythe plate/rod construct assembly complete and sterile packed, and toprovide a range of sterile sizes ready for surgery. As can beunderstood, this implant system also requires a minimal number ofinstruments, simplifying the surgical implant procedure and allowing theinstruments to be supplied in a sterile state.

It is noted that various individual features of the inventive processesand systems may be described only in one exemplary embodiment herein.The particular choice for description herein with regard to a singleexemplary embodiment is not to be taken as a limitation that theparticular feature is only applicable to the embodiment in which it isdescribed. All features described herein are equally applicable to,additive, or interchangeable with any or all of the other exemplaryembodiments described herein and in any combination or grouping orarrangement. In particular, use of a single reference numeral herein toillustrate, define, or describe a particular feature does not mean thatthe feature cannot be associated or equated to another feature inanother drawing figure or description. Further, where two or morereference numerals are used in the figures or in the drawings, thisshould not be construed as being limited to only those embodiments orfeatures, they are equally applicable to similar features or not areference numeral is used or another reference numeral is omitted.

The phrase “at least one of A and B” is used herein and/or in thefollowing claims, where A and B are variables indicating a particularobject or attribute. When used, this phrase is intended to and is herebydefined as a choice of A or B or both A and B, which is similar to thephrase “and/or”. Where more than two variables are present in such aphrase, this phrase is hereby defined as including only one of thevariables, any one of the variables, any combination of any of thevariables, and all of the variables.

The foregoing description and accompanying drawings illustrate theprinciples, exemplary embodiments, and modes of operation of theinvention. However, the invention should not be construed as beinglimited to the particular embodiments discussed above. Additionalvariations of the embodiments discussed above will be appreciated bythose skilled in the art and the above-described embodiments should beregarded as illustrative rather than restrictive. Accordingly, it shouldbe appreciated that variations to those embodiments can be made by thoseskilled in the art without departing from the scope of the invention asdefined by the following claims.

What is claimed is:
 1. A spinal fixation device, comprising: at leastone bone screw having: a head with a nut connection section; and a screwportion shaped to screw into bone; at least one locking nut having: aninternal bore shaped to connect to the nut connection section of the atleast one bone screw; and an exterior wall; a bearing having an exteriorand defining an internal bore shaped to fit therein: the nut connectionsection of the head; and the exterior wall of the at least one lockingnut; at least one slider: defining an internal bore shaped to fit theexterior wall of the at least one locking nut therewithin; and having anexterior with a given shape; and an elongate plate construct having: afirst end defining a first opening shaped to accept the exterior of thebearing therein; and a second end defining a second opening shaped toaccept the at least one slider therein and having a corresponding shapeto the given shape to permit the at least one slider to slide in atleast a portion of the second opening.